The ability of CGRP to downregulate TNFα when challenged by a bacterial agent has been demonstrated in periodontal diseases in which CGRP promotes osteoblast proliferation and reduces the gram-negative Prophyromonas gingivalis-induced osteoblast cell apoptosis [71] through the suppression of the cleaving of c-Caspase-3 and c-Caspase-8, two intracellular cascade molecules associated with apoptotic progression. Here, CALCA is linked to periodontal disorder.