Jiang et al. [14] showed that the ALDH1A1-positive lung cancer cells could generate tumors in vivo, furthermore, the expression of ALDH1A1 was positively correlated with the stage and grade of lung tumors and related to a poor prognosis for the patients with early-stage lung cancer, which suggested that ALDH1A1 could be a potential prognostic factor and therapeutic target for treatment of the patients with lung cancer. Here, ALDH1A1 is linked to lung cancer.