HTR1A was one of GPCRs and is one of the most widely expressed and abundant subtypes of serotonin receptors.[13] HTR1A, binding with its ligand 5‐HT (also known as serotonin), resulted in conformational changes and signaling pathway activation, such as PI3K/Akt and MAPK/ERK pathways.[20, 21] Studies regarding the function of HTR1A are mainly focused on the nervous system, such as regulating depression by regulating self‐tolerance by deregulating gene expression. Here, HTR1A is linked to major depressive disorder.