Expression levels of CELF1 in lung cancer tissues. (A) Expression levels of CELF1 in 10 lung cancer tissues compared with normal lung tissues analyzed by real time PCR. (B) Expression of CELF1 in lung cancers at different stages analyzed by real time PCR. (C) Comparison of the survival rate of patients with N1 and N2 lymph node metastasis and without lymph node metastasis. (D) Comparison of the survival rate with levels of CELF1 expression. The values represents the mean from three independent experiments; bars represent SD. *P < 0.05, **P < 0.01 compared with controls.