The development of this cancer involves a sequence of genetic mutations, particularly in the adenomatous polyposis coli (APC), Kirsten rat sarcoma viral oncogene homolog G12D (KRAS), human epidermal growth factor receptor 2 immunohistochemistry 3+ (HER-2 IHC3+), checkpoint kinase 2 (CHEK-2) and tumor protein P53 (TP53) genes, which lead to the malignant transformation of normal epithelial cells [2]. The gene discussed is CHEK2; the disease is cancer.