ATF2 and fatty liver disease: For example, although the Atf6 and Atf2 mRNA levels were similar between the IUGR and control groups, both proteins were significantly increased in the IUGR group, especially Atf6, which was upregulated until 12 W. Atf6 is a transcription factor with a major role in the regulation of ER quality control proteins, and plays dual protective and pathologic roles in fatty liver disease due to ER stress (14).