TP53 and cancer: Most of these were established dependencies of cancer cells, including Nutlin‐3a sensitivity and MDM2 gene fitness independently associated with TP53 mutation status; BRAF and PIK3CA mutation induced drug and CRISPR dependency; olaparib sensitivity mediated by the presence of EWSR1‐FLI1 fusion, also recapitulated by FLI1 essentiality profile; MCL1 inhibitor and gene fitness associations with BCL2L1 expression, and Nutlin‐3a sensitivity and MDM2 gene fitness associated with BAX expression (Figs 5C and EV5E and F).