CHEK2 and breast cancer: Such candidate gene approaches revealed that germline mutations of TP53[7], PTEN[8], ATM[9], CHEK2[10], BRIP1[11], PALB2[12], NBS1[13] and RAD50[14] are correlated with breast cancer risk, but to a much more moderate extent than BRCA1 and BRCA2. Therefore, new unbiased genomic approaches are needed for identifying genetic factors that influence breast cancer susceptibility.