Mucosal associated invariant T cells (MAIT cells), invariant mucosal T cells, are a relatively novel population of innate immune cells that produce inflammatory cytokines IFN-γ, TNF-α and IL-17, or independently, or by stimulation with microorganisms, present in a smaller percentage in the liver and blood of patients with PBC compared to controls [1,49,50]. This evidence concerns the gene IL17A and primary biliary cholangitis.