IL17A and periodontitis: Inflammation:  The oral microbiota linked to periodontitis was found to   directly activate interleukin-17-positive (IL-17+) γδ T cells.   These activated γδ T cells played a crucial role in activating   the IL-17/signal transducer and activator of transcription 3   (STAT3) pathway, and promoting the infiltration of   M2-tumor-associated macrophages (TAMs) in   OSCC proliferation.