CDKN1B and colon carcinoma: Moreover, in cell lines derived from oral squamous cell carcinoma (HSC-2, HSC-3, and HSC-4) and colon carcinoma (DLD-1), α-mangostin induced G1 arrest by downregulating CDK4, CDK2, cyclin D3, and cyclin E, as well as through the upregulation of the p27kip1 and p21waf1/cip1 CDK inhibitors [40,42].