SREBF1 and steatosis: To definitively determine the roles of AMPK and SREBP-1c in NS5A-induced steatosis, Hepa1–6 and HepG2 cells were co-transfected with NS5A and SREBP-1c for 40 h and then treated with 1 mmol/L AICAR for another 8–12 h before qRT-PCR, Western blotting and Oil Red O staining assays.