Given that p53 immunoreactivity in most carcinomas has been regarded as a surrogate marker for, although not a proof of, gene mutation or inactivation, the observed correlations between MCM-2 or MCM-5 on one hand and p53 on the other hand might be indicative of the positive effect exerted by mutant-type p53 on cell cycle progression. This evidence concerns the gene TP53 and carcinoma.