We next evaluated somatic alterations in 36 DDR genes covered by our NGS panels, including ATM, ATR, ATRX BAP1, BLM, BARD1, BRCA1/2, BRIP1, CHEK1/2, CDK12, EMSY, ERCC1, FAM175A FANCA/C/D2/E/F/G/L/M, MRE11A, NBN, RAD50/51/52, RAD51B/C/D, RAD54L, PALB2, RECQL, RECQL4, and WRN. We found 286 (47.6%) breast cancer patients had DDR gene mutations. This evidence concerns the gene CHEK1 and breast cancer.