CD80 and ovarian carcinoma: Accordingly, in an ovarian carcinoma-bearing mice model, IFN-γ-stimulated M-MDSC increased MHC class II, CD80, and IL-10 expression, and induced CD4+CD25+ Treg in a CTLA-4/CD80-dependent manner (65), which is in line with our results on IL-10-producing GM-CSF/IL-6 M-MDSC.