Fujii et al. [18] showed that follistatin, a TGF-B/activin binding protein, accelerated the regeneration following PH, however, had no effect on regeneration induced by the PVL whereas Mueller et al. [19] noticed that the mRNA of cell proliferation marker histone2B significantly elevated at 24 h after PH but it was delayed at 48 h following PVL. The gene discussed is FST; the disease is periventricular leukomalacia.