However, another result of the present study showed that the mean difference of ProGRP content was significantly between the two groups before and after chemotherapy, and logistic regression analysis showed that increased ProGRP content was an influencing factor of increased sPD-L1 expression, and that sPD-L1 and ProGRP changed to the same extent during progression, remission, and stability in SCLC patients. The gene discussed is SPDL1; the disease is small cell lung carcinoma.