Moreover, it has been observed that the loss of the tumor suppressor gene Cyclin Dependent Kinase Inhibitor 2A (CDKN2A), which encodes for p16 INK4A, is one of the most common abnormalities in BC, causing uncontrolled activation of CDK4/6, which leads to abnormal cell proliferation [15,16]. This evidence concerns the gene CDKN2A and breast cancer.