HMOX1 and colorectal carcinoma: Immunohistochemical analysis of surgical resections of CRC tissues and non-tumoral adjacent parenchyma showed that, compared to the relatively lower expressions of HO-1 in adjacent normal colorectal tissues and polyps tissues (11/37, 29.7%; most are grade 0–1) (Figure 1a, b), HO-1 expressed in 72 of 118 tumor tissues (61.0%) with mostly moderate to strong staining (P < 0.01; Figure 1c-g, most are grade 2–3).