ABCG4 positivity rate was higher in NSCLC than in normal lung tissues (48.6% vs. 0%, P<0.001) and ABCG4 expression was significantly associated with poor differentiation, higher tumor node metastasis (TNM) stage, and adenocarcinoma histological type (all P<0.001). The gene discussed is ABCG4; the disease is non-small cell lung carcinoma.