ERBB2 and cancer: Despite evidence that emodin directly interacts with several molecular targets involved in inflammation and cancer, including casein kinase II, Her2/neu, topoisomerase II, and heat shock protein 90 (Hsp90) [13], it is unclear whether other proteins are involved in the mechanism by which emodin exerts its pharmacological effects; however, a comprehensive understanding of its mechanism of action is important for the development of emodin as a new therapeutic agent.