Table 1. Relative affinities of IgG... | American Society of Hematology

Table 1.

Relative affinities of IgG subclasses for various Fcγreceptors.

	FcγRI	FcγRIIa	FcγRIIb	FcγRIII
Molecular Mass	70 kDa	40 kDa	40 kDa	50–80 kDa
IgG Subclass Specificity	1 ≥ 3 > 4 > 2	3 > 1 > 2 > 4	3 ≥ 1 > 4 > 2	1 = 3 > 2 = 4
IgG Affinity	10⁻⁷–10⁻⁹ M	> 10⁻⁷ M	> 10⁻⁷ M	> 2 × 10⁻⁷ M

	FcγRI	FcγRIIa	FcγRIIb	FcγRIII
Molecular Mass	70 kDa	40 kDa	40 kDa	50–80 kDa
IgG Subclass Specificity	1 ≥ 3 > 4 > 2	3 > 1 > 2 > 4	3 ≥ 1 > 4 > 2	1 = 3 > 2 = 4
IgG Affinity	10⁻⁷–10⁻⁹ M	> 10⁻⁷ M	> 10⁻⁷ M	> 2 × 10⁻⁷ M