TSPAN9 and autoimmune thyroid disease: To explore the potential role of TSPAN9 in HCC, we performed KEGG pathway enrichment analysis, and the results unveiled that downregulation of TSPAN9 was correlated to multiple immune and cancer pathways (Figure 1(e)), including antigen processing and presentation, intestinal immune network for IgA production, autoimmune thyroid disease, and allograft rejection signaling pathway.