Compared with tumor slices from HSPC patients, we clearly demonstrated here, in the CRPC slice cultures, an increase in the number of residual and thus unrepaired IR‐induced γH2AX and 53BP1 foci upon pretreatment with olaparib or cisplatin as evidenced by increased PiER and CisER indices, respectively. The gene discussed is TP53BP1; the disease is neoplasm.