Additionally, we included a panel of 40 negative control sgRNAs (targeting non‐human genes such as Luc, LacZ, Ren, Rosa26, and scrambled sequences) and 24 positive control sgRNAs (targeting cancer essential genes such as PCNA, RPA3, CDK, etc.; SourceData S2 and Figure S1A,B, Supporting Information). Here, REN is linked to cancer.