CREB1 and steatosis: ATF3 is a member of the CREB family of basic leucine zipper transcription factors and functions both as a transcriptional activator or repressor.32 ATF3 is induced in the livers of a rat model of severe steatosis and human patients with NAFLD, correlative with the ER stress status.33 ATF3 was also induced in the livers of SIRT7−/− mice (Figure 3J; Data S2).