It was previously reported that cytoplasmic RAP1 was detected in breast cancer tissue, and its pathology scores were positively correlated with the tumor grades.17 To test the hypothesis that cytoplasmic RAP1 is a biomarker for higher-grade NSCLC, we immunostained for RAP1 and quantified its cytoplasmic and nuclear expression in 93 lung adenocarcinoma and 75 lung squamous cell carcinoma tissues. The gene discussed is TERF2IP; the disease is breast cancer.