Abstract
Chen et al demonstrated that regulator of G protein signaling (RGS) 4 promotes gastric cancer (GC) progression by activating the focal adhesion kinase/phosphatidyl-inositol-3-kinase/protein kinase B pathway and inducing epithelial-mesenchymal transition. Although their multilevel approach integrating clinical data, functional assays, and xenograft models demonstrated a key role for RGS4 in GC pathogenesis, several limitations should be considered. The mechanism of the RGS4-focal adhesion kinase interaction remains unclear, specifically whether it involves direct binding or intermediaries. The clinical analysis of 90 patients lacks stratification by GC subtypes or immune features, potentially limiting generalizability. Furthermore, fully validating RGS4's oncogenic role requires additional studies, including functional assays in chemotherapy-resistant and metastatic cell lines, metastasis models including orthotopic implantation and tail vein injection, and comparison with other RGS family members. Addressing these via targeted mechanistic studies and expanded clinical validation could strengthen RGS4's potential as a therapeutic target in GC.