LRR1 is an essential gene in normal and cancerous human cells. (A) Cell number after 7 d of culture normalized to control cells (sgCNTL). Two-sample Student’s t test; n.s., P = 0.97; ***, P = 1.5 × 10⁻⁴ (n = 2 technical replicates). NTC, non-treated control, where cells were not transfected with sgRNAs. (B) Histogram of LRR1 knockout (KO) effect (CERES score) in a panel of cancer cell lines from Broad and Sanger DepMap projects (n = 769 and 317 cell lines, DepMap Public 20Q2 release). A larger negative gene KO effect indicates that a gene is more likely to be essential in a given cell line. (C) Violin plot of median KO effect (across all cell lines) for all genes, essential genes, and essential ribosomal genes from Broad and Sanger DepMap projects. Dashed lines indicate median KO effect for LRR1. List of ribosomal genes is obtained from the HUGO Gene Nomenclature Committee. (D) Violin plot of Bayes factor for all genes, core fitness genes, and core fitness ribosomal genes in RPE-1 cells (Hart et al., 2015). Dashed line indicates Bayes factor for LRR1. A larger Bayes factor indicates that a gene is more likely to be essential.