CDKN1A and skin neoplasm: Meeran and Katiyar [55] reported that GSPs inhibited skin cancer cell (A431 cells) proliferation which was mediated through the inhibition of cyclin-dependent kinases (Cdk) Cdk2, Cdk4, and Cdk6 and cyclin D1, D2, and E, increase in cyclin-dependent kinase inhibitors (Cdki), Cip1/p21 and Kip1/p27, and enhance binding of Cdki-Cdk.