Immunohistochemical analysis of melanomas arising in NAM- or placebo-treated patients within the ONTRAC skin cancer chemoprevention trial [11] demonstrated that melanoma lesions occurring in NAM-treated patients were more infiltrated by CD4+ and CD8+ lymphocytes than in the placebo, indicating a contribution of the immune response to its pharmacological effect [23]. This evidence concerns the gene CD8A and skin neoplasm.