TP53 and neoplasm: We identified “true positive” TP53 alterations from high-confidence SNVs, CNVs, SVs, and fusions in TP53, annotating tumors as “activated” if they harbored one of the p.R273C or p.R248W gain-of-function mutations43 or “lost” if (1) the patient had a Li-Fraumeni syndrome (LFS) predisposition diagnosis, (2) the tumor harbored a known hotspot mutation, or (3) the tumor contained two hits (e.g., both SNVs and CNVs), suggesting that both alleles were affected.