SESN2 and cancer: More recently, it has been shown that SESN2 expression is regulated by activating the transcription factor 4 (ATF4) under endoplasmic reticulum (ER) stress condition triggered by nelfinavir and bortezomib in various cancer cell lines, HeLa, MDA-MB-45 and OVCAR3 (Brüning et al. 2013).