IFNG and melanoma: PD-L2 can be induced on dendritic cells, macrophages, activated T cells (8, 11, 21, 42), B cells (123–125), and cancer cells by IL-4 through IL-4R/STAT6 in inflammatory macrophages (126), the NF-κB pathway in dendritic cells (8), and IFN-β/IFN-γ in melanoma cells (47).