Among the seven cancer cell lines available for comparisons, 4SP65 was more effective as a cytostatic agent than PRIMA-1 or APR-246 by 4.3- to 21-fold in TP53 wild-type cells, 2.3- to 30-fold in TP53 mutant cells, and 3.3- to 16-fold in TP53-null SKOV3 cells. This evidence concerns the gene TP53 and cancer.