ATF4 and pancreatic neoplasm: In pancreatic cancer cells, however, not only was AMPK level or its activation (p‐AMPK) altered by GW3965 treatment but knocking down AMPK by siRNA did not affect REDD1 level in response to GW3965, suggesting the specificity of ATF4 and TXNIP in regulating REDD1 and mTOR in these cancer cells.