We read with high interest the paper by Hadjiliadis et al, who report a 5- to 10-fold increased risk of colon cancer in patients with cystic fibrosis (CF), and a 25 to 30 time greater in patients with CF after organ transplantation1; patients with CF also carry a many-fold increased risk of several other cancers.2 CF is characterized by altered chloride transport across cell membranes, and altered exchange with bicarbonate in the bronchi, skin glands, bile canaliculi, and ovarian and pancreatic ducts.