Western blot analysis of p21 phosphorylation in untreated (A,D), human recombinant PKC α treated (B,E) and human recombinant PKC α and lambda protein phosphatase treated (C,F) human recombinant p21 fusion proteins. Antibodies tested include p-p21 (C-8): sc-377514 (A,B,C) and p21 (C-19): sc-397 (D,E,F).