Through observation of serum ProGRP and NSE concentrations In each group, we discovered that the serum levels of ProGRP (314.43±5.54 pg/mL) and NSE (124.54±3.84 pg/mL) In the SCLC group were greater than those In the healthy control group, the benign lung disease group, and the NSCLC group, with the difference being statistically significant (P<0.05). Here, ENO2 is linked to small cell lung carcinoma.