CRISPR/Cas9 genetic screen identifies cancer-relevant RNA modification. (A) Scheme of dropout screen (top) and average log₂ FC (bottom) of 150 human RMPs, including positive controls (Ctrs) in 18 cell lines at day 22 of the experiment. Illustrated is every sixth RMP. (B) Correlation of RMP gene effect in targeted CRISPR experiments and genome-scale CRISPR (Chronos) (depmap.org). Each dot represents the average effect across all tested cell lines. (C) Dose-response curve evaluating the effect of different concentrations of cytarabine (AraC) in blood cancer lines with corresponding IC₅₀ values. (D-E) Illustration of synthetic lethality screen (D) and treatment regimen with AraC (E) in OCI-AML2 cells. (F-G) Volcano plot illustrating log₁₀ statistical significance (FDR) vs log₂ FC of sgRNA abundance (F) and MAGeCK-negative enrichment score of averaged gRNAs per gene (G) identifying essential RMPs in AraC-treated cells after 22 days in culture. (H) Correlation between TRMT5 protein expression and IC₅₀ values in response to AraC treatment (Sanger, GDSC1) in lymphoid and myeloid cancer lines (blood) and all other cell lines. (I) CRISPR MYC, TRMT112, TRMT5, and METTL3 gene effects (Chronos) (depmap.org) across 1150 cancer cell lines. (J) Cancer lines with significant (left) and nonsignificant (right) correlation of CRISPR TRMT5 gene effect and IC₅₀ values of AraC treatment. FC, fold-change; FDR, false discovery rate; IC₅₀, 50% inhibitory concentration.