Another key distinction between BRCA1 and BRCA2 in terms of cell cycle protein expression involves type D cyclins (D1, D3), their associated CDK such as CDK4, and the CDKIs p16, p21, and p27, which showed a lower expression in BRCA1 compared to BRCA2 carcinomas [65]. The gene discussed is BRCA2; the disease is carcinoma.