FcγRIIIa^NK-158V binds more IgG than does FcγRIIIa^NK-158F. IgG binding by NK cells from individuals either homozygous FcγRIIIA-158FF (▪) or homozygous FcγRIIIA-158VV (□) was compared, irrespective of the FcγRIIIa-48L/R/H genotype. At least three different donors of each genotype were tested. The level of cytophilic IgG and the binding of IgG1, IgG3, and IgG4 was significantly higher in NK cell from FcγRIIIA-158VV individuals (P < .05 in all cases).