RASGRP2 (RAS guanyl-releasing protein 2) is a calcium- and diacylglycerol-regulated guanine nucleotide exchange factor that primarily activates the small GTPase Rap1, with secondary activity toward RRAS, RRAS2, NRAS, and KRAS 1. Its central function is mediating inside-out αIIbβ3 integrin activation in platelets through Rap1-dependent signaling, essential for platelet aggregation and adhesion under flow conditions 12. RASGRP2 also functions in T-lymphocyte and neutrophil adhesion, likely through similar integrin activation mechanisms 3. Clinically, loss-of-function RASGRP2 mutations cause platelet-type bleeding disorder-18 (BDPLT18), an autosomal recessive condition characterized by moderate-to-severe bleeding, normal platelet counts, and impaired aggregation responses to multiple agonists 45. Remarkably, heterozygous carriers remain asymptomatic with normal hemostasis, indicating that a single functional allele suffices for normal bleeding prevention 1. Beyond hematology, RASGRP2 is expressed in vascular endothelial cells where it may regulate vasculogenesis and serve as a protective factor for vessel integrity 6. Recent evidence identifies RASGRP2 as an autoantigen in multiple sclerosis pathogenesis 3 and as an immune-related biomarker in lung adenocarcinoma, where it correlates with improved prognosis through mitochondrial-dependent apoptosis regulation 7.