The Wall Street Analyst Forum’s 17 th Annual Analyst Conference

Forward Looking Statements… During this presentation, our remarks will include forward-looking statements. These statements are neither promises nor guarantees, but involve risks and uncertainties that could cause actual results to differ materially from those anticipated or indicated. Any forward-looking statements should be considered in light of such risks and uncertainties including, without limitation, those detailed in the Company's filings with the SEC, including those discussed in the prospectus supplement.

Our Current Mission “To eradicate mortality from colorectal cancer through early detection using applied genomics”

The Promise of EXAS Large unmet medical market No controversy- early detection provides less costly treatment & saves lives Pre-Gen-Plus is first “average risk” marketed genomics diagnostic for CRC Molecular biology & mutations associated with CRC are well known Ability to detect these mutations in stool, which provides us with a biological advantage PreGen-Plus is the most accurate non- invasive diagnostic available

Five-year Survival Rate for CRC Two-thirds of Patients are Diagnosed Too Late Early Diagnosis Late Diagnosis Dukes ADukes BDukes CDukes D 37% of Patients63% of Patients 80% 55% 10% 95%

A Success and a Failure Source: World Health Organization, American Cancer Society FOBT Colo Flex Sig Screening Colo Pap Colorectal Cervical 0 10,000 50,000 60,000 40,000 Colorectal vs. Cervical Cancer Death Estimates

The Opportunity in CRC 20% Screened 80% Unscreened People Over the Age of 50 Should Be Screened Regularly Increases by 4 Million Each Year People Over 50 (Millions)

A New Genetic Model

Validation of PreGen Plus PreGen-Plus is a single test comprised of 23 molecular markers of CRC PreGen-Plus has significant clinical publications –Gastroenterology (2000,04, and 04) –Clinical Colorectal Cancer (2003) –New England Journal of Medicine (2004) –Journal of Molecular Diagnostics 2004 Blue Shield California Technology Assessment Patients are more compliant –Single whole stool specimen –No bowel preparation –No medication or dietary restrictions –No sample manipulation

Clinical Utility = f (A x C x D) AccuracyCompliance Distribution / Access FOBT Flex Sig Colonoscopy PreGen-Plus™

Develop Cancer Specific Non-Invasive Assay Demonstrate Superiority to Already Recommended Screening Modality in Average Risk Population (MCS) Introduce Commercial Assay-PreGen-Plus™ through LabCorp Product Adoption/Guideline Inclusion/Payor Policy Our Short Term Strategy

Observations & Confirmations

The Importance of Guideline Inclusion Multi-Society Task Force/ACS 13 State Mandates NCQA/HEDIS Guidelines Requirement for self insured Positive impact on payors Will tip the scales for some doctors

How to get into Guidelines Requirements Peer reviewed studies to prove equality/superiority Acceptability to patients Comparable or lower complication rates & costs Feasibility in general clinical practice Thought leader support Demand

General 50% reduction in age-adjusted cancer mortality rates 25% reduction in age-adjusted cancer incidences rates American Cancer Society 2015 Challenge Goals Colorectal Cancer Increase to 75% the proportion of people over the age of 50 years who have CRC screening consistent with ACS guidelines –e.g., FOBT, flex sig, DCBE, colonoscopy Reduce Cancer Increase Screening

Payors Managed Care / Self-Insured Employers Clinical Studies Thought Leaders Provider Pressure Membership Demand Cost Effectiveness NCQA/HEDIS Guidelines

EXAS Value Drivers Guideline Inclusion Payor Policy Decisions Strong Development Strategy –Improved Assay for CRC –Assay for Pre-Cancer

Applied Research Stage I √Develop Cancer Specific Assay √Demonstrate Superiority to Already Recommended Screening Modality in Average Risk Population (MCS) √Introduce Commercial Assay through partner –Guideline Inclusion Stage II –Increase Performance Cancer Adenomas –Decrease Cost Stage III –Apply Assay to Platform Kit Development Development Strategy

Assay Improvements (Stage II) Increase DNA Yield –Effipure DNA Prep. Sample Handling –Stabilize Sample During Collection Method Marker Reformulation –De Novo Mutation Scanning (e.g. APC MCR) –Hypermethylation –Cancer Detection –Pre-Cancer Detection

Next Generation Assay performance Tumor tissue analysis

The Future Other Screening Opportunities More Depth in Colorectal Cancer Expanding Internationally

The Wall Street Analyst Forum’s 17th Annual Analyst Conference