In contrast, leads for drug sensitivities unique to familial gastric cancer due to germline CDH1 mutations are to date largely derived from a synthetic lethality and drug screen in an isogenic CDH1 knockout breast fibroblast model (MCF10A CDH1(−/−)) [12], CDH1-negative systems overexpressing wild type versus mutant forms of CDH1 [26, 27], or correlative tissue studies of the early unique T1a lesions of prophylactic gastrectomy specimens [8, 10]. Here, CDH1 is linked to Familial gastric cancer.