ATF4 and neoplasm: Activating transcription factor 4 (ATF4) may also be a potential therapeutic target for glioma, because the expression and activation of ATF4 are enhanced in glioma cells, leading to a significant up-regulation of system Xc– expression, thereby reducing the sensitivity of tumor cells to ferroptosis, and thus promoting tumor cell proliferation, tumor angiogenesis, and other malignant characteristics[28].