Ig gamma-4 chain C region (IGHG4) is also known as IgG4 H Chain C Region, is a member of many immunoglobulin G developed and secreted by effective B cells. IgG4 is an antibody moleculer induced by infection. Immunoglobulins are composed of four peptides chain-two heavy gamma chains and two light chains. Ig gamma-4 chain C region / IGHG4 contains three constant regions of IgG4 H chain (CH1, CH2, CH3) and with a 12 aa hinge region between CH1 and CH2.