Since all MRGPRX2 agonists can activate MCs to release proteases, cytokines, and histamine,5 the observed increase of MRGPRX2 agonists in various inflammatory skin diseases is likely to contribute to at least some aspects (e.g. pruritus) of the respective skin diseases by activating and degranulating skin MCs. The gene discussed is MRGPRX2; the disease is Pruritus.