It is thought that cancers that are defective for other components of the HRR pathway, such as ATM, CHEK1, CHEK2, NBN, BRIP1, MRE11, RAD50, RAD51B, RAD51C, RAD51D, RAD54L, PALB2 and BARD1, may also benefit from PARPi (7). Here, CHEK2 is linked to cancer.