RB1 and neoplasm: No NUDT15 loss were detected in the tumor cells of 23 RB1 expressed samples, whereas 14 out of 21 (66.7%) RB1‐loss samples exhibited co‐loss of NUDT15 in tumor cells with p = 3.9 × 10−6 (Figure 4A,B), supporting the frequent co‐loss of NUDT15 in CRPC patients with RB1 loss.