IDO1 and pancreatic adenocarcinoma: In addition, CYP1B1 expression was positively correlated with both IDO1 and TDO2 expression in skin melanoma (SKCM), squamous lung carcinoma (LUSC), diffuse large B-cell lymphoma (DLBC) and pancreatic adenocarcinoma (PDAC) (Supplementary Fig. 1b).