The role of host factors in the etiology of pancreatic cancer has received a paucity of systematic investigation. Anecdotal reports and one population-based study have supported the concept that familial clustering of this disease exists. We have studied a kindred with a cancer-associated genoder-matosis known as familial atypical multiple mole melanoma (FAMMM) syndrome (hereditary dysplastic nevus syndrome). Three key relatives have manifested pancreatic carcinoma. Since FAMMM may account for as much as 10% of the total malignant melanoma burden, its association with pancreatic cancer harbors important public health implications. Given the fact that the etiology of pancreatic cancer remains enigmatic, it is important to investigate all possible clues to its causality, including the potential role of host factors.