NBN and melanoma: To determine whether melanomas that have dysregulation of the MRN complex or ATM may be sensitive to PARP inhibitors, we performed independent knockouts of ATM, NBN, and MRE11 in 2 melanoma cell lines, MeWo (TWT) and A375 (BRAF-mutant), followed by olaparib cell viability assays (Supplemental Figure 6).