The p53 oncosuppressor is the gene which has been found to be most fre
quently altered in human cancers. How the p53 gene contributes to tumo
r induction and progression is presently being investigated by numerou
s researchers whose specialties range from basic science to clinics. T
his is a brief overview of the hypotheses on p53 role in tumorigenesis
and the possible use of p53 analyses in tumor prognosis and therapy.