Unlike other cancers, Gal-9 research in lung cancer has focused more on clinical studies, and how Gal-9 actually affects the development of lung cancer is still enigmatic in the current stage of research, and it is an urgent issue to dig out the effect of Gal-9 in lung cancer from the tissue or even single-cell level in the future. The gene discussed is LGALS9; the disease is lung carcinoma.