RAD51D and neoplasm: To determine an underlying cause for CSig3 activity, we evaluated each tumor for aberrations in 1 of 11 genes with well-described roles in mediating HRR: BRCA1, BRCA2, RAD51, RAD51B, RAD51C, RAD51D, RAD54L2, BRCA1 associated RING domain 1 (BARD1), GEN1 Holliday junction 5′ flap endonuclease (GEN1), PALB2, and BRCA1 interacting helicase 1 (BRIP1), hereafter designated as a core HRR gene (HRG; Figure 1, A and B).