We analyzed distinct SCLC cell clusters across various disease stages and found that the SCLC-A-MKI67 and SCLC-A-CRIP2 fractions were relatively high in both stages I–II and III–IV and were significantly reduced upon neoadjuvant therapy, accompanied by a notable increase in AT2 cells. The gene discussed is MKI67; the disease is small cell lung carcinoma.