Previous immunohistochemical studies have shown that sGC-α and sGC-β are both expressed in ICC of lower esophageal sphincter, stomach, small intestine, caecum, colon, and internal anal sphincter (Salmhofer et al., 2001; Iino et al., 2009; Cobine et al., 2014; Lies et al., 2014, 2015), and at least from immunohistochemical analyses, sGC is more abundant in ICC than in SMCs. This evidence concerns the gene SGCB and intrahepatic cholangiocarcinoma.