The impact of checkpoint kinase 2 (CHEK2) mutations as a prognostic factor in the pathogenesis of breast cancer was studied also by Ansari [9], who underlines that, in cell signaling pathways, CHEK2 is regulated by the influence of upstream genes, and, that, in addition, CHEK2 regulates a number of downstream genes. Here, CHEK2 is linked to breast cancer.