ATF4 and breast cancer: We showed that very low doses of JQ1 and bortezomib (BTZ) induced ferroptosis in basal‐like breast cancer through integrated responses mediated by enhanced lysosomal function, increased ferritinophagy, glutaminolysis, TCA cycle, oxidative phosphorylation, and activation of activating transcription factor 4 (ATF4), a master regulator of the integrated stress response (IRS) and amino acid metabolism.[16] Ferroptosis‐to‐apoptosis transition was coupled to enhanced ER stress, XBP1, and ATF4/CHOP activation concomitant with a PE/PC‐ metabolic shift.