1. Basic, Underlying Data for Figures 1-3

2. Legend – Supplemental Figure 1. GC-Rich Regions of Altered Methylation: Comparison of DEN-Initiated, 0.05% PB-promoted Precancerous Tissue (CAR WT, 23 wk DEN/PB) to Control (CAR WT, 23 wk DEN). RsaI/MspI (pink symbols), RsaI/HpaII (green symbols), and BfaI/BssHII (orange symbols) restriction digestion and AP-PCR was performed on DNA isolated from C3H/He CAR WT mouse liver initiated with a single dose of DEN, and then administered water or 0.05% PB (w/w) for 23 wk. Regions of hypomethylation and hypermethylation are evident (a). Regions of new methylation resulting from PB treatment are shown in terms of peak area for each PCR product size (b). The y-axis scale was expanded in order to facilitate visualization of all data points. Subsequently, 2 regions of new methylation whose peak areas exceeded the scale of the chart were labeled with their corresponding peak areas (c). A table tallying the regions of altered methylation for each treatment are shown as an inset in each figure. Regions of hypomethylation and hypermethylation are expressed in terms of the treated mean for each PCR product size as a percent of the control mean for each PCR product size. All changes projecting below the x-axis represent decreases in methylation (hypomethylation) while all of those above the x- axis represent increases in methylation (hypermethylation). All 100% hypomethylations are considered to be significant, and only the hypermethylations and partial hypomethylations that were significantly different from control values (Student’s t-test, p<0.05) are shown.

3. Supplemental Figure 1a. GC-Rich Regions of Altered Methylation: Comparison of DEN-Initiated, 0.05% PB-promoted Precancerous Tissue (CAR WT, 23 wk DEN/PB) to Control (CAR WT, 23 wk DEN) DigestHypomethylated RAMsHypermethylated RAMsTOTAL RAMs MspI145 HpaII6612 BssHII130

4. Supplemental Figure 1b. GC-Rich Regions of Altered Methylation: Comparison of DEN-Initiated, 0.05% PB-promoted Precancerous Tissue (CAR WT, 23 wk DEN/PB) to Control (CAR WT, 23 wk DEN) DigestNew Methylations MspI10 HpaII2 BssHII5

5. Supplemental Figure 1c. GC-Rich Regions of Altered Methylation: Comparison of DEN-Initiated, 0.05% PB-promoted Precancerous Tissue (CAR WT, 23 wk DEN/PB) to Control (CAR WT, 23 wk DEN) DigestNew Methylations MspI10 HpaII2 BssHII5

6. Legend – Supplemental Figure 2. GC-Rich Regions of Altered Methylation: Comparison of DEN-Initiated, 0.05% PB-promoted Tumor Tissue (CAR WT, 32 wk DEN/PB) to Control (CAR WT, 23 wk DEN). RsaI/MspI (pink symbols), RsaI/HpaII (green symbols), and BfaI/BssHII (orange symbols) restriction digestion and AP-PCR was performed on DNA isolated from C3H/He CAR WT mouse liver initiated with a single dose of DEN, and then administered water or 0.05% PB (w/w) for 32 wk. Regions of hypomethylation and hypermethylation are evident (a). The y-axis scale was expanded in order to facilitate visualization of all data points. Subsequently, 1 region of hypermethylation whose percent consensus control exceeded the scale of the chart was labeled with its corresponding value (b). Regions of new methylation resulting from PB treatment are shown in terms of peak area for each PCR product size (c). The y-axis scale was expanded in order to facilitate visualization of all data points. Subsequently, 4 regions of new methylation whose peak areas exceeded the scale of the chart were labeled with their corresponding peak areas (d). A table tallying the regions of altered methylation for each treatment are shown as an inset in each figure. Regions of hypomethylation and hypermethylation are expressed in terms of the treated mean for each PCR product size as a percent of the control mean for each PCR product size. All changes projecting below the x-axis represent decreases in methylation (hypomethylation) while all of those above the x-axis represent increases in methylation (hypermethylation). All 100% hypomethylations are considered to be significant, and only the hypermethylations and partial hypomethylations that were significantly different from control values (Student’s t-test, p<0.05) are shown.

7. DigestHypomethylated RAMsHypermethylated RAMsTOTAL RAMs MspI23427 HpaII11112 BssHII170 Supplemental Figure 2a. GC-Rich Regions of Altered Methylation: Comparison of DEN-Initiated, 0.05% PB- promoted Tumor Tissue (CAR WT, 32 wk DEN/PB) to Control (CAR WT, 23 wk DEN)

8. Supplemental Figure 2b. GC-Rich Regions of Altered Methylation: Comparison of DEN-Initiated, 0.05% PB- promoted Tumor Tissue (CAR WT, 32 wk DEN/PB) to Control (CAR WT, 23 wk DEN) DigestHypomethylated RAMsHypermethylated RAMsTOTAL RAMs MspI23427 HpaII11112 BssHII170

9. Supplemental Figure 2c. GC-Rich Regions of Altered Methylation (New Methylations Only): Comparison of DEN-Initiated, 0.05% PB-promoted Tumor Tissue (CAR WT, 32 wk DEN/PB) to Control (CAR WT, 23 wk DEN) DigestNew Methylations MspI20 HpaII28 BssHII25

10. Supplemental Figure 2d. GC-Rich Regions of Altered Methylation (New Methylations Only): Comparison of DEN-Initiated, 0.05% PB-promoted Tumor Tissue (CAR WT, 32 wk DEN/PB) to Control (CAR WT, 23 wk DEN) DigestNew Methylations MspI20 HpaII28 BssHII25

11. Legend – Supplemental Figure 3. GC-Rich Regions of Altered Methylation: Comparison of DEN-Initiated, 0.05% PB-promoted CAR KO Tissue (CAR KO, 23 wk DEN/PB) to Control (CAR KO, 23 wk DEN). RsaI/MspI (pink symbols), RsaI/HpaII (green symbols), and BfaI/BssHII (orange symbols) restriction digestion and AP-PCR was performed on DNA isolated from C3H/He CAR KO mouse liver initiated with a single dose of DEN and then administered water or 0.05% PB (w/w) for 23 wk. Regions of hypomethylation and hypermethylation are evident (a). Regions of new methylation resulting from PB treatment are shown in terms of peak area for each PCR product size (b). The y-axis scale was expanded in order to facilitate visualization of all data points. Subsequently, 1 region of new methylation whose peak area exceeded the scale of the chart were labeled with its corresponding peak area (c). A table tallying the regions of altered methylation for each treatment are shown as an inset in each figure. Regions of hypomethylation and hypermethylation are expressed in terms of the treated mean for each PCR product size as a percent of the control mean for each PCR product size. All changes projecting below the x-axis represent decreases in methylation (hypomethylation) while all of those above the x-axis represent increases in methylation (hypermethylation). All 100% hypomethylations are considered to be significant, and only the hypermethylations and partial hypomethylations that were significantly different from control values (Student’s t-test, p<0.05) are shown.

12. Supplemental Figure 3a. GC-Rich Regions of Altered Methylation: Comparison of DEN-Initiated, 0.05% PB- promoted CAR KO Tissue (CAR KO, 23 wk DEN/PB) to Control (CAR KO, 23 wk DEN) DigestHypomethylated RAMsHypermethylated RAMsTOTAL RAMs MspI505 HpaII100 BssHII210

13. Supplemental Figure 3b. GC-Rich Regions of Altered Methylation (New Methylations Only): Comparison of DEN-Initiated, 0.05% PB-promoted CAR KO Tissue (CAR KO, 23 wk DEN/PB) to Control (CAR KO, 23 wk DEN) DigestNew Methylations MspI12 HpaII3 BssHII0

14. Supplemental Figure 3c. GC-Rich Regions of Altered Methylation (New Methylations Only): Comparison of DEN-Initiated, 0.05% PB-promoted CAR KO Tissue (CAR KO, 23 wk DEN/PB) to Control (CAR KO, 23 wk DEN) DigestNew Methylations MspI12 HpaII3 BssHII0