A Newly Discovered Fc Receptor that Explains IgG-Isotype Disparities in Effector Responses

The known IgG FcRs primarily mediate inflammation by interacting with IgG1, even though IgG2 isotypes tend to be more pathogenic. Nimmerjahn et al. (2005) have just identified a novel FcγR that binds IgG2 but not IgG1, potentially explaining differences in biological activity that are seen with various IgG isotypes (Nimmerjahn et al., 2005)