CHEK2 and breast cancer: Germline mutations were observed in 14.4% of IBC patients and they were mainly related in in 7.3% of cases to BRCA1/BRCA2 mutations, whereas 6.3% of patients had mutations in other breast cancer-related genes, such as PALB2, CHEK2, ATM, and BARD1; finally, 1.6% had mutations in genes that were not related to breast cancer [156].