1. Supplementary Table S1 Clinical exposure for palbociclib, fulvestrant and chemotherapeutic agents used in this study. Palbociclib (1)*Paclitaxel (2)*Doxorubicin (3)*Fulvestrant (4)* Clinical Dose125 mg175 mg/m260 mg/m2500 mg/5ml Cmax202 nM0.43 µM1.16 µM46 nM Cave calculation144 nM0.078 µM0.25 µM30 nM based on AUC(AUC 0-24hr 1982 ng.h/ml)(AUC 0-120hr 7993ng.h/ml)(AUC 0-24hr 358ng.h/ml)(AUC 0-15day 13100 ng.hr/ml) * Numbers in parenthesis indicate reference number.

2. Supplementary Table S2. Cell cycle analysis in human bone marrow mononuclear cells treated with palbociclib for 4 days. Dead CellG1 PhaseS PhaseG2/M Phase Vehicle6.25% (± 0.59%)53.96% (± 2.33%)27.93% (± 0.98%)11.75% (± 1.91%) Palbociclib 0.1uM4.32% (± 0.84%)60.98% (± 3.32%)20.61% (± 0.84%)13.19% (± 1.72%) Palbociclib 0.3uM4.66% (± 0.14%)67.4% (± 2.04%)16.10% (± 1.49%)7.04% (± 0.39%) Palbociclib 1uM4.68% (± 1.17%)79.23% (± 1.17%)9.99% (± 2.59%)4.55% (± 0.73%)

3. Supplementary Figure S1 AB

4. Supplementary Figure S2

5. Supplementary Figure S3 **

6. Supplementary Figure S4