On the other hand, in Lian et al's[15] study, it seems PDE5 inhibitors will not increase or decrease the melanoma risk in fewer prescriptions (1–6) and lower dosage (below 25 tablets) (HR: 1.07, 95%CI: 0.82–1.41; HR: 1.00, 95%CI: 0.75–1.32). This evidence concerns the gene PDE5A and melanoma.