CXCL8 and renal cell carcinoma: To determine if AMPK is an upstream regulator of Nox4 and mediates hypoxia-induced IL-6 and IL-8 production, we exposed RCC 786-O cells to normoxic, hypoxic, or pre-incubated RCC cells with the AMPK activator, AICAR and subjected the cells to hypoxia for 48 hours.