Pathophysiological role of cytoglobin, the fourth globin in mammals, in liver diseases.

Cytoglobin (Cygb), a stellate cell-specific globin, has recently drawn attention due to its association with liver fibrosis and cancer. In human and rodent livers, Cygb is expressed only in stellate cells and can be utilized as a marker to distinguish stellate cells from hepatic fibroblast-derived myofibroblasts. Loss of Cygb accelerates liver fibrosis and cancer development despite its etiology in mouse models of chronic liver injury. This review discusses the current perception of the distribution, regulation and function of Cygb with regard to liver diseases, with an emphasis on its role in tumorigenesis. Further investigation of Cygb may shed new light on the biology of organ carcinogenesis.