SOX1 and lung adenocarcinoma: First, we examined the methylation levels of SOX1 in 473 lung adenocarcinoma (LUAD) and 370 lung squamous cell carcinoma (LUSC) samples from The Cancer Genome Atlas (TCGA) using the UALCAN website (http://ualcan.path.uab.edu, accessed on 1 July 2019).