TPH1 and inflammatory bowel disease: They contribute to mucosal inflammation in inflammatory bowel disease (IBD) (likely via IL-17/IFN-γ driven pathways) (145) and participate in the exocrine gland damage seen in primary Sjögren’s syndrome (pSS) (potentially through ectopic IL-21 production supporting autoreactive B cells) (146), all of which indicates that Tfh-like cells might have a close relationship, or at least emerge in very similar state with Tph.