ENO2 and small cell lung carcinoma: Observation of ProGRP and NSE levels in the serum of SCLC patients at different stages suggested that the serum levels of ProGRP (268.35±4.66 pg/mL) and NSE (98.41±3.76 pg/mL) in extensive-stage SCLC were higher than those in limited-stage SCLC [ProGRP (154.42±4.55 pg/mL) and NSE (57.69±6.33 pg/mL)], with the difference deemed statistically significant (P<0.05).