NAA20 and cancer: To test the reliability of cancer cell-derived CERES scores for general essentiality in physiological processes we also included five genes identified in our screen, N6amt1, Wbscr22, Nat10, Naa20 and Naa50, which had not previously been studied in ground-state pluripotent mESCs but showed noteworthy depletion across the 739 cancer cell lines tested (Fig. 1d).