In this study, dietary histidine deficiency activated the PEPK-signalling pathway and IRE1-signalling pathway with increased core gene expression of pepk, grp78, eif2α, atf4, chopα, ire1, xbp1, traf2, ask1, and jnk1, indicating that dietary histidine deficiency induced ERS. This evidence concerns the gene XBP1 and amelogenesis imperfecta type 1G.