We found that not only did exosomal PITPNA-AS1 accurately distinguish SCLC patients from non-cancer patients with the highest AUC (0.983) and the highest sensitivity and specificity out of all the ROC curve analyses, but it also distinguished SCLC from LUSC very well, showing excellent sensitivity, specificity, and AUC value. The gene discussed is PITPNA; the disease is small cell lung carcinoma.