DDAH1 and lung cancer: Figure 4B–E summarized the maker gene analysis on the DNAS-identified lung cancer subtypes, respectively. In particularly, LOC100130933 and DDAH1 were exhibited relatively high expression in LUAD (Joehanes et al. 2016, Huang et al. 2020), while DSG3 and TPRXL were expressed at high levels in LUSC (Savci-Heijink et al. 2009, Sui et al. 2017). Therefore, LOC100130933 and DDAH1 may stimulate the growth of adenocarcinoma in lung cancer, and DSG3 and TPRXL can contribute to mark squamous cell carcinoma in lung cancer.