Hyperbilirubinemia is common in intensive care unit patient occurring as many as 40% of patients. Increased level of bilirubin is found in various forms of cancer like Cholangiocarcinoma, Ampullary carcinoma and Pancreatic adenocarcinoma. Radiation therapy is widely recognized and most common treatment of these carcinomas. This book gives comprehensive information about hitherto poorly understood effect of increased level of bilirubin on induction of apoptosis in various immune cells. Further this book provides a deep insight into molecular mechanism of radiopotentiating effects of bilirubin. How increased level of bilirubin augment infection susceptibility is explained in great details.