The human leukocyte receptors fall into two functional groups, namely, proinflammatory, activating‐type receptors (FcγRI, FcγRIIa, FcγRIIc, FcγRIIIa and FcγRIIIb, which are also known as CD64, CD32a, CD32c, CD16a and CD16b, respectively) and the anti‐inflammatory, inhibitory‐receptor group (FcγRIIb also called CD32b) which was the first immune checkpoint described.