E2F1 and small cell lung carcinoma: Moreover, univariate survival analysis revealed that E2F1 (P < 0.01, Figure 2A) and clinical stage (P < 0.01 Figure 2B) were prognosis factors in SCLC patients, while other factors including gender (P = 0.768), age (P = 0.818), smoking (P = 0.827), tumor size (P = 0.411) were not significant.