Figure 4: Protein level of the cell cycle regulators, CDK2, CDK, p21CIP1, p16INK4a, analyzed by immunoblot in SK-Mel28 cell clones that stably overexpress the DsRed-LSF fusion protein or control DsRed. α-tubulin served as internal control. Relative intensity of p21 and p16 were obtained from three independent experiments. **P<0.01; *P<0.05.