OPRD1 and Pruritus: In contrast, although the δ-opioid receptor (OPRD1) associated with MRGPRX2, it did not trigger mast cell degranulation, suggesting a limited contribution to peripheral itch signaling.<h4>Conclusions</h4>Our findings identify a novel peripheral mechanism of opioid-induced itch mediated by OPRM1/MRGPRX1 heterodimers in sensory neurons.