To the Editor: We read with great enthusiasm an interesting and exciting viewpoint by Lin,1 who believed that the core relationship between a tumor and its host microenvironment is the nutritional and signal interactions between cancer stem cells and endothelial cells.Our group is long-termly engaged in the study of glioma and glioma stem cell, and we also put much conc upon the research of tumor invasion.rnOne of the most marked bionomics of malignant gliomas is invasion, which leads to the spreading of tumor masses along nerve fibers and blood vessels, and even distant dissemination.However, a benign tumor grows only by expansive growth.Therefore, it is of a quite benefit to illuminate or even partly illuminate the tumor-host social (THS) relationship.