IDO1 and cancer: To determine the relevance of IDO1 that is expressed in cancer cells in PDAC, we first analyzed IDO1 mRNA by real-time RT-qPCR in 10 PDAC cell lines (AsPC-1, BxPC-3, Capan-1, Capan-2, CFPAC-1, HPAF-II, MIA PaCa-2, PANC-1, Panc 10.05, and SU.86.86) and compared the levels to that in HPDE, a normal pancreatic ductal epithelial cell line.