TP53 and neoplasm: In SB28 cells, a total of 1,445 sgRNAs led to significantly decreased cell growth while 137 sgRNAs led to increased cell growth, with Cdkn2a and Tp53 repression comprising 2 of the top enriched sgRNA hits, thus identifying a requirement of Cdkn2a or Tp53 for cell growth, consistent with human tumor mutation data (Supplemental Figure 14A).