Based on the comparable expression profile of CTLA-4 on T lymphocytes and FcγRs on tumor-infiltrating innate effector cell subsets in humans and hFcγR mice, we next evaluated whether anti-CTLA-4 mAbs of a human isotype promoted depletion of intra-tumoral Treg cells in vivo in a similar manner to that mediated by murine FcγRs (Selby et al., 2013, Simpson et al., 2013). Here, CTLA4 is linked to neoplasm.