TP53 and cancer: To further explore the role of p53 mutation status as a predictor of sensitivity to PRMT5 inhibition and to identify additional predictive biomarkers, we analyzed the association of the anti-proliferative response to PRMT5 inhibitor across 240 cell lines (Fig. 6A, as defined by activity area or gIC50) and the mutation profiles of individual genes in 185 human cancer cell lines for which both proliferation and exome-seq data were available.