The adenine-to-guanine (A/G) substitution at nucleotide 870 (CCND1 G870A polymorphism, rs603965) and excessive cyclin D1 activity are common in numerous human tumors, including breast cancer, lung cancer, head and neck cancers, gastric cancer, gynecological cancers, blood-related cancers, and CRC [6], [7]. The gene discussed is CCND1; the disease is breast carcinoma.