To ascertain whether VHL was involved in the synergy between topoisomerase inhibitors and 15d-PGJ2, we compared the synergism of anti-cancer agents with 15d-PGJ2, in VHL-positive cell lines (Caki-2, ACHN and RCC4 (+)) and VHL-negative cell lines (786-O cells and RCC4(-)). This evidence concerns the gene VHL and cancer.