LTK (leukocyte receptor tyrosine kinase) is a transmembrane receptor with intrinsic tyrosine kinase activity that transduces extracellular signals into intracellular responses 12. Upon activation by ALKAL1 or ALKAL2 ligands at the cell surface, LTK undergoes ligand-induced kinase activation, triggering the mitogen-activated protein kinase (MAPK) pathway and phosphorylation events 234. Beyond canonical kinase signaling, LTK participates in endoplasmic reticulum-to-Golgi protein transport and ER export site regulation 2. Chimeric protein studies demonstrate LTK's capacity to promote neurite outgrowth and cell survival, though its precise physiological function remains incompletely characterized 56. Clinically, LTK has emerged as an oncogenic driver in non-small-cell lung cancer (NSCLC) through CLIP1-LTK fusion formation, which exhibits constitutively activated kinase activity and transformation potential 7. A patient with CLIP1-LTK-positive NSCLC demonstrated clinical response to lorlatinib, an ALK inhibitor, establishing LTK as a potentially actionable therapeutic target 7. Additionally, LTK ligand ALKAL1 modulates macrophage phenotype by promoting MerTK phosphorylation, contributing to tumor-associated immunosuppression 8. These findings position LTK as both a physiological regulator of cellular growth and a significant cancer driver.