CRISPR screening identifies Herc1 as a modulator of Ara-C response in murine AML cells. (A) Schematic of our CRISPR/Cas9–based screening pipeline developed in murine AML cells. (B) Representation of CRISPR/Cas9–based dropout screen performed in MA and HM cells in the presence of Ara-C (IC₅₀). (C) Representation of overlapping genes that are providing sensitivity (NormZ score, <2) and resistance to Ara-C (>2). (D) Pathway enrichment analysis of sensitizing genes using the KEGG database. (E) Expression analysis of the 39 overlapping sensitizers in the hematopoietic and lymphoid tissues from the CCLE database (n = 188). (F) Schematic of CRISPR-based competition assay. (G) Competitive growth assay ± Ara-C (50 nM) or H₂O (vehicle) in MA cells. Data are represented as the ratio of mCherry⁺ normalized to day 0 (t3 independent transductions). Significance was determined using 2-way analysis of variance (ANOVA), followed by a Dunnett test. ∗P ≤ .05. AMPK, adenosine monophosphate-activated protein kinase; KEGG, Kyoto Encyclopedia of Genes and Genomes.