CDKN1A and non-small cell lung carcinoma: Loss of PKCε activity in NSCLC cells is associated with induction of p21Cip1, prolonged G1 → S transition in response to serum, and reduced activation of cdk2 complexes (Bae et al., 2007), indicating that this isozyme suppresses p21Cip1 accumulation to facilitate cell cycle progression.