Due to FcRn’s role in IgG homeostasis, we hypothesized that elevated mAb CL in CMT-167 and LLC TB mice, and decreased FcRn gene (Fcgrt) expression in liver of LLC TB mice, as previously reported (16, 18, 35), would translate to decreased FcRn protein expression in immune cells of CMT-167 and LLC mice. The gene discussed is FCGRT; the disease is tuberculosis.