RALGPS2 is a Ras-independent guanine nucleotide exchange factor (GEF) that activates the small GTPase RalA 1. The protein contains a C-terminal pleckstrin homology (PH) domain that binds phosphatidylinositol-4,5-bisphosphate and localizes to membranes, and a central PxxP motif that recruits SH3 domain-containing proteins like Grb2 and PLCγ 1. While its GEF domain activates RalA, the PH-PxxP domains function as dominant negatives, suggesting regulatory complexity 1. Mechanistically, RALGPS2 promotes cytoskeletal reorganization through actin remodeling and is essential for tunneling nanotube formation via interaction with RalA and the transmembrane protein LST1 2. In lung cancer, RALGPS2 controls cell cycle progression and survival through modulation of Skp2, p27, and p21 cell cycle regulators—functions largely independent of canonical RalA/RalB signaling 3. The protein also induces Ras-independent transcriptional activation of c-fos 1. Clinically, RALGPS2 has emerging significance in cancer prognosis. Three competing endogenous RNA interactions involving RALGPS2 (SNHG1-miRNA-RALGPS2) predict poor lung adenocarcinoma prognosis 4. Additionally, RALGPS2 expression differences distinguish vasodilator-responsive pulmonary arterial hypertension patients 5, and genetic variants near RALGPS2 associate with type 2 diabetes susceptibility 6.