Ishigami K, et al. - Researchers assessed MicroRNA-31 (miR-31) expression in bile duct cancer tissues and evaluated its association with prognosis, as well as the effects of several cytokines on miR-31 expression. Eighty-one samples of bile duct cancer tissues were included in this analysis. As compared to the normal bile duct epithelial cells, MiR-31 expression in bile duct cancer cells was significantly higher. The findings suggested that miR-31 could be a promising biomarker that reflects IL-6 expression in bile duct cancer tissues, and it may also predict poor prognosis.