Cell differentiation, which is tightly regulated, is normally thought to proceed unidirectionally as a cascade reaction, however, there is increasing evidence that some kinds of cells can go backward to more primitive cells, such as tissue-specific stem cells, or transdifferentiate into other-lineage cells. Kondo has been shown that oligodendrocyte precursor cells (OPC) in the central nervous system (CNS) can acquire multipotency in a special condition and redifferentiate into neurons and astrocytes as well as oligodendrocytes. Moreover, he has found that the chromatin remodeling and histone modifications are involved in the OPC reversion. Because the nucleus in the most of cells retains every information for the body plan, it is a spontaneous idea to imagine that the epigenetic modification by the extracellular signals might be able to induce the cells to dedifferentiate or to transdifferentiate into other lineage cells. In addition, Kondo has also found that various types of cancer cell lines contain stem-like cells, which are essential for their malignancy. Together with the findings that the epigenetic modification is also involved in cancer development, the epigenetics would be the central machinery for any cell fate decision. Using neural stem cells, OPC and stem-like cells in glioma, Kondo's lab, seeks the extracellular signals, intracellular factors and epigenetic mechanism, which are involved in the reversion, transdifferentiation, and/or stem cell maintenance, and will apply the knowledge for the CNS therapy.