CHEK2 and melanoma: Numerous other associations have been observed for specific cancers for individuals with heterozygous CHEK2 variants, including sarcoma, stomach cancer, male breast cancer, melanoma, pancreatic cancer, esophageal cancer, endometrial cancer, and testicular cancer.2,26 For more common cancers (eg, endometrial, skin), there was no evidence of association for these in either cohort.