Between 3% and 5% (n = 107) of all combinations have synergy in at least 25% of cell lines from these populations (41 combinations for basal-like breast cancer, and 28 and 38 for MSS and KRAS-mutant colon cancer, respectively), with some having exquisite specificity of synergy in the population of interest. The gene discussed is KRAS; the disease is colonic neoplasm.