It is known that SP, through the NK-1R, is a crucial mediator in inflammatory mechanisms (vasodilatation, vascular permeability increase, edema formation, leukocyte infiltration) and that the undecapeptide promotes the synthesis of inflammatory cytokines (IL-1, IL-6, IL-12, tumor necrosis factor-alpha) by monocytes; in addition to favor an inflammatory response, the level of cytokines has been associated with an increased tumor progression [103,104,105]. The gene discussed is TACR1; the disease is neoplasm.