RB1 and osteosarcoma: In contrast, adding IL-1β had either no or a lesser suppressive effect on IFN-γ-induced IDO1 mRNA expression levels in colonic (HCT116, CCK-81), leukocytic (HAP1, THP-1), lung (A549, PC-3), breast (MCF7, YMB-1), pancreatic (MIA PaCa-2, KP-2), kidney (293T, KMRC-1), ovarian (RMG-I, RKN), placental (BeWo), splenic (OVTOKO), cervical (Ca Ski, HeLa), osteosarcoma (U2OS), foreskin fibroblastic (HFF), and retinoblastic (Y79, WERI-Rb-1) cell lines (Figure 1B).