In addition, increased gut permeability during aging and obesity also allows for increased exposure of pathogenic bacteria and LPS to GC B cells in the intestinal TLS, accelerating B cell inflammatory function, senescence-like changes, leading to less IgA beneficial for homeostasis, decreased IgA diversity, and increased IgA autoAbs [261, 267–269], further contributing to inflammaging and immunosenescence [263] (Fig. 1B). The gene discussed is CD79A; the disease is obesity due to melanocortin 4 receptor deficiency.