ATF4 and metabolic disease: By orchestrating the expression of a wide range of genes, ATF4 is involved in many pathophysiological processes beyond ER stress, including redox balance, cell cycle, cell differentiation, autophagy, apoptosis, ferroptosis, amino acid uptake, glucose and fatty acid metabolism, etc., thus playing pivotal roles in a variety of diseases like cancer, neurodegenerative disease, metabolic disease, etc. (Tang et al., 2024; Xiao et al., 2023; He et al., 2023; Wei, Zhu & Liu, 2015; Ryan et al., 2021).