CLDN1 and small cell lung carcinoma: The exosome miR-141 is transported into HUVEC cells and targets KLF12 to promote angiogenesis in small cell lung cancer (SCLC), and miR-375-3p destroys vascular endothelial cells by directly binding to the 3′UTR of the tight junction protein CLDN1 and negatively regulating its expression tight junctions (Mao et al., 2020; Mao et al., 2021).