TP53 and cancer: Furthermore, in the DepMap database (Cancer Dependency Map: https://depmap.org/portal), comparing the effect of specific gene loss on growth across more than 1,000 cancer cell lines on proliferation, Matrin3 scored negative on average, compared with the expected negative and positive scores, respectively, for an essential control gene (PLK1) and a tumor-suppressor gene (p53) (Figures S1Q and S1R).