STAT3 and cancer: Considering the previously described importance of HSP60 in cancer cells [35] and our data showing that STAT3 overexpression/knockdown significantly increased/reduced HSP60 levels in CNE1 and HNE1 cells, we studied the effect of HSP60 in the therapeutic efficacy of PQR309 + gemcitabine using HSP60-overexpressing NPC cells (Supplementary Fig. S9A, B).