They reported that insulin-like growth factor-2 (IGF-2) was highly expressed among both of the comparative diseases i.e. periodontitis and MDD.15 Recently in 2023, a thorough systematic review verified the direct association of NPY, SP, neurokinin A, CGRP, and VIP, with periodontitis.16 The aim of the current review was to reveal the mediating role of specific pro or anti-inflammatory cytokines, chemokines neuropeptides, and pathogens in the association of chronic periodontitis and somatosensory disorders. This evidence concerns the gene VIP and major depressive disorder.