Lymphatic metastasis in non‐small cell lung cancer: recent discoveries and novel therapeutic targets

Lung cancer is the 2nd most common and 1st deadliest cancer worldwide [1]. It presents an enormous burden on society in China, because of its high incidence and mortality rate [2, 3]. About 80%-85% of lung cancers are non-small cell lung cancer (NSCLC). Lymphatic metastasis is a critical event in disease progression that influences clinical treatment and determines the prognosis for NSCLC [4]. Unlike the tightly joined smooth muscle cells and pericytes that make up the walls of blood vessels, lymphatic endothelial cells (LECs) of lymphatic capillaries loosely overlap due to the lack of a complete basementmembrane. Due to the high interstitial pressure in tumor tissues and the loose structure of lymphatic capillaries, initial lym-