- IFN-α-2b inhibits immediately the activity of CYP1A2 (p = 0.001) and 2D6 (p < 0.001) in patients with high-risk resected melanoma, - inhibition of CYP2C19 was detected for the first time at day 26 (p < 0.001) after the initiation of high-dose IFNα-2b treatment (20 MU/m2/day i.v for 5 days/weeks during 4 weeks and 10 U/m2/day s.c for 3 days/week x 48 weeks), - no significant inhibition was seen for CYP2E1. This evidence concerns the gene CYP2C19 and melanoma.