EI24 is an autophagy-associated transmembrane protein that functions as a multifaceted regulator of cell survival and death pathways. As a p53-target gene, EI24 acts as a negative growth regulator by inducing apoptosis through the p53-mediated pathway 1. Beyond apoptosis, EI24 regulates critical cellular processes including autophagy flux, ER stress adaptation, and tumor immunity 23. Mechanistically, EI24 localizes to the endoplasmic reticulum-mitochondria interface where it tethers these organelles to regulate autophagy through interactions with VDAC1, IP3R, and GRP75 2. During ER stress, EI24 coordinates IRE1 signaling and calcium homeostasis to promote cell adaptation by inhibiting IRE1 activation under nonstressed conditions and preventing ER calcium depletion upon stress 3. Clinically, EI24 expression is aberrant across diverse cancer types and associates with patient prognosis 45. EI24 maps to chromosome 11-q24, a region frequently altered in human cancers 6. Reduced EI24 expression through deletion and methylation correlates with cancer progression, particularly in cervical carcinoma, and predicts worse prognosis 7. However, EI24's tumor-suppressive role appears context-dependent, as Ei24 overexpression showed no protective effect in a colorectal cancer model 8. EI24 represents a promising biomarker and therapeutic target for cancer management.