Several novel gut-associated lymphoid cells have been described. They are of different origins and follow different maturation processes but share the same GALT role – to rapidly respond to pathogens and secrete effector cytokines. Such multi-layered protection systems highlights the susceptibility of mucosal sites to invading agents. The mucosal route is the most frequent way for entering of pathogenic infections into the host. Robust engagement of a variety of lymphoid cells patrolling the epithelial layer also reflects evolutionary pressure and arms race between immune systems and pathogens escaping its control.