Abstract Single-strand DNA repair (ssDR) is critical for preventing genomic catastrophe. AnaNeo Therapeutics was founded by experts in DNA repair mechanisms. Extending our team’s previous fundamental ssDR studies we analyzed >61,000 tumors for somatic mutations, generated isogenic mutant/wild-type cell line pairs, screened two isogenic cell line pairs with small molecule libraries, performed computational and experimental synthetic lethality (SL) screens and used state-of-the-art Schrodinger Maestro drug docking software to nominate small molecule ssDR SL hits. Here in this Phase I STTR project we propose to validate candidate targets and small molecule inhibitors. Overall, this study will nominate innovative ssDR SL precision therapy targets and small molecule hits for lead optimization in future Phase II SBIR studies.