NFKB1 and cancer: While there was little difference in the abundance of many non-targeting-control sgRNAs between days 0 and 14, sgRNAs targeting genes known to be essential in MCL, such as CCND127, SOX1128,29, genes in the BCR and NFκB pathways, or pan-dependent genes in many cancers were substantially depleted by at least twofold on day 14 (Fig. 1a, b, Supplementary Fig. 1a, b, and Supplementary Data 1).