lncRNA dropout CRISPR-Cas9 screen in MM cell lines. (A) Schematic representation of the CRISPR screening pipeline. (B) Spearman's correlation between pgRNA read count profiles (from DNA collected 30 days after transduction and selection of the library) across screen replicates = 0.85 and 0.88, respectively, for AMO-1 and ABZB, with color bars on top/left indicating cluster membership obtained via hierarchical clustering (complete distance method). (C) Representation of pgRNA abundance log fold changes (logFCs) in DNA collected 30 days after library transduction and selection vs plasmidic amounts for 3 groups of pgRNAs: nontargeting (negative controls [median logFC = 0.27 and 0.35, respectively, for AMO-1 and ABZB]), targeting ribosomal protein genes (control essential genes, median logFC = −0.68 and −0.43, with a logFC ≤−0.5, corresponding to a MAGeCK FDR ≤20%), and lncRNAs, across the 2 screens. Each point represents 1 of the 12 472 pgRNAs in the library with coordinates on the y-axis indicating the median logFC across screen replicates. (D) Gene-wise MAGeCK robust rank aggregation (RRA) scores for significant dependencies identified in the 2 screens at an FDR ≤20%. Top essential control genes, dependencies that are private to each cell line and shared across them (as per the color scheme) are highligted. (E) Number of significantly essential lncRNAs (at an FDR ≤20%) in the 2 screened cell lines and their overlap. MOI, multiplicity of infection.