c-Myc overexpression attenuates U0126 differentiative effects. Immunoblotting with specific antibodies for indicated proteins of cell lysates from c-Myc polyclonal population of RD cells left untreated or treated with U0126. α-tubulin expression shows the loading of samples. The histograms (right panel) show the values of fold increases over the control, arbitrarly set at 1, obtained by densitometric analysis of the immunoblottings. Similar results were obtained in two experiments.