Mulder et al. have identified unique TAMs (IL4I1+ CD274 (PD-L1)+ IDO1+), which accumulate in the tumor periphery in a T cell-dependent manner via interferon-γ (IFN-γ) and CD40/CD40L-induced maturation from IFN-primed monocytes36. The gene discussed is IDO1; the disease is neoplasm.