[20], [32]–[34] Furthermore, inhibition of DHODH was proposed by White et al as a potential anti-melanoma therapy. [22] To investigate the degree to which DHODH inhibition by leflunomide contributes to the anti-proliferative effects in melanoma cells, we performed uridine rescue experiments in A375 and MDA-MB-435S melanoma cells [30], [35], both of which express abundant levels of AhR (Figure 1E and 6A). This evidence concerns the gene AHR and melanoma.