ATF4 and colorectal carcinoma: To clarify the relationship between DHEA-triggered ER stress and autophagy induction, we blocked ER stress by the pharmacological inhibitor 4-PBA, downstream PERK UPR pathway ATF4, and CHOP gene expression by shRNA genetic silencing, as well as autophagy function by genetic silencing Autophagy related 5 (ATG5) gene of the CRC cells for 48 h in the presence or absence of DHEA (200 μM).