PKM and rheumatoid arthritis: As a key enzyme in the glycolytic pathway, the PKM2 expression of RA-FLS was significantly increased under hypoxic conditions, while inhibition of glycolytic activity by glycolytic inhibitor 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one(3PO) dramatically reverse pro-inflammatory mechanisms including invasion, migration, cytokine secretion, and the signaling pathways of hypoxia-inducible factor-1α(HIF-1α), pSTAT3, and Notch-1IC (33).