CHRNA7 and hepatocellular carcinoma: Representative IHC images of the α7-nAChR in non-cancerous and cancer tissues of different TNM stages are shown in Figure 2A. HCC specimens characterized as TMN stage III exhibited strong α7-nAChR immunopositivity; TMN stage II tissues showed moderate staining, stage I specimens showed mild staining, and corresponding normal liver (NL) tissues showed negative staining (Figure 2A).