CDKN1A and prostate cancer: Treatment of the mutant p53P223L/V274F DU145 human prostate cancer cell line with either VMY or PRIMA-1 alone showed only modest expression of the known down-stream p53 target gene, p21CIP1/WAF1, while co-treatment with both PRIMA-1 and VMY led to the induction of p21CIP1/WAF1, without affecting the total p53 expression levels, thus demonstrating restoration of p53 activity by PRIMA-1 (Fig. 3B).