Colorectal HCT116 cancer cells with CRISPR-engineered phospho-mimetic S183D and S185D mutations at the endogenous TP53 locus demonstrated reduced expression of p53-regulated genes, increased resistance to doxorubicin, and a marked drop in apoptosis, closely resembling the cooperativity mutant E180R phenotype. The gene discussed is TP53; the disease is cancer.