CD79A and infection: In the face of exogenous infections, the organism secretes IgA to protect intestinal epithelial cells from infection by commensal flora, and immunoscreens commensal flora to maintain intestinal immune homeostasis (Fagarasan et al., 2010; Sonnenberg et al., 2012); Meanwhile, GM and flora metabolites stimulation induces gut dendritic cells and primitive B cells to secrete protective IgA, which regulates the development and function of immune cells in the body (Yu et al., 2018).