To examine the relevance of BEX4 gain-of-function in human cancers, we compared BEX4 levels in 191 patients with non-small cell lung cancer (NSCLC), including 107 squamous cell carcinoma (SqCC, 56.0%), 71 adenocarcinoma (ADC, 37.2%), 9 large cell carcinoma (4.7%), 2 adenosquamous cell carcinoma (1.0%), and 2 sarcomatoid carcinoma (1.0%), immunohistochemically using anti-BEX4 antibody. Here, BEX4 is linked to adenocarcinoma.