LRIG3 (leucine-rich repeats and immunoglobulin-like domains 3) is a single-pass transmembrane protein with dual roles in development and cancer biology. During embryonic development, LRIG3 may regulate craniofacial and inner ear morphogenesis, potentially controlling lateral semicircular canal formation by restricting NTN1 expression within the otic vesicle epithelium. In cancer pathogenesis, LRIG3 functions as a tumor suppressor gene. Mechanistically, LRIG3 regulates cell proliferation, apoptosis, invasion, and migration through modulation of growth factor signaling pathways, particularly EGFR and MET/PI3K/Akt cascades 1. Decreased LRIG3 expression correlates with increased cancer cell proliferation and invasion across multiple malignancies 2345. A soluble ectodomain form (sLRIG3) also exhibits tumor-suppressive activity 6. Clinically, LRIG3 expression is a significant prognostic indicator: high expression associates with improved overall survival in cervical adenocarcinoma, glioblastoma, and prostate cancer 763. Recently, LRIG3 was identified as a target of let-7b-5p microRNA, with this pathway modulating microglial pyroptosis and promoting motor function recovery in spinal cord injury models 8. These findings establish LRIG3 as clinically relevant for cancer prognosis and potentially therapeutic intervention.