A total of 554 nodes and 9978 edges were displayed in PPI network (Figure S1, Supplemental Digital Content, http://links.lww.com/MD/O352), and the top 10 genes (PTPRC, RPS27A, UBA52, CD8A, ITGB2, GNB2L1, TYROBP, CD86, TLR4, and FCGR3A) were selected as hub CD8 + T cell-related genes in SCLC (Fig. 3A, Table S2, Supplemental Digital Content, http://links.lww.com/MD/O353). The gene discussed is CD8A; the disease is small cell lung carcinoma.