FCGR3A and neoplasm: Moreover, polymorphisms in the genes coding for the receptors mainly responsible for ADCC, i.e., Fc fragment of IgG, low affinity IIa, receptor (FCGR2A, also known as CD32) and FCGR3A (also known as CD16a), have been shown to influence the response of cancer patients to most tumor-targeting mAbs [77].