Based on our previous finding that HCA binds directly to PKM2 to decrease STAT3 phosphorylation in prostate cancer cells24 and a study by Harris et al. showing that RORγt is a downstream effector of the STAT3 pathway and is linked to Th17 differentiation27, we investigated whether HCA affected the PKM2-STAT3 pathway in Th17 cells. Here, STAT3 is linked to prostate carcinoma.