Interestingly, the T/Tgenotype expresses higher mean serum levels of IL-4 compared to theC/T and C/C genotypes (Toumi et al., 2013).Higher IL-4 levels might be contributing to the polarization of autoreactive Thlymphocytes towards the Th2 pathway, inducing proliferation of autoreactive Blymphocytes and facilitating immunoglobulin class switching to IgG4 that ispathogenic in pemphigus. The gene discussed is IL4; the disease is pemphigus.