In this study we have investigated cancer risks in members of Swedish melanoma-prone families with an inherited mutation in the tumor suppressor gene CDKN2A. We find significantly increased risks among carriers not only for melanoma but also for non-melanoma cancers, in particular pancreatic, lung, head and neck and gastro-esophageal cancers. We show a positive association between tobacco smoking and these non-melanoma cancers among mutation carriers. It appears as smoking potentiates the effect of the mutation and greatly enhances the cancer risks in carriers. This is the first study to show an association between smoking and cancer in CDKN2A mutation carriers. Our study has important implications for counseling and monitoring of members of melanoma-prone families with inherited CDKN2A mutations. Carriers of CDKN2A mutations should be informed about the importance of abstinence from tobacco smoking to decrease their risk for non-melanoma cancers. (By Dr Hildur Helgadottir, http://jmg.bmj.com/content/early/2014/06/15/jmedgenet-2014-102320 )