PIK3CA and rheumatoid arthritis: Furthermore, the activation of the PI3K/Akt/HIF-1α signaling pathway has been found to play a pivotal role in mediating hypoxia-induced EMT transformation and invasion in rheumatoid arthritis-fibroblast-like synoviocytes (RA-FLSs) [9] and hypoxia-induced EMT and chemoresistance in hepatocellular carcinoma [10].