SMC4 and lung carcinoma: In the Cox regression model, univariate Cox regression indicates that the T stage (p < 0.05), N stage (p < 0.001), M stage (p < 0.001), SMC4 (p = 0.049), pathologic stage (p < 0.001), residual tumor (p < 0.001) and Age (p = 0.022) were correlated with the lousy prognosis of lung cancer (Table 1).