[1] Seoul Natl Univ Hosp, Dept Neurol, Stem Cell Res Ctr, Clin Res Inst,Stroke & Stem Cell Lab, Seoul 110744, South Korea
[2] Seoul Natl Univ, Neurosci Res Inst, SNUMRC, Program Neurosci, Seoul 151, South Korea
[3] Seoul Natl Hosp, Program Publ Hlth Serv, Seoul, South Korea
[4] Korea Ctr Dis Control & Prevent, Dept Epidem Intelligence Serv, Seoul, South Korea
[5] Gachon Med Univ, Inst Regenerat Med, Inchon, South Korea
[6] Univ British Columbia, UBC Hosp, Dept Med, Div Neurol, Vancouver, BC V5Z 1M9, Canada
[7] Seoul Natl Univ, Tumor Immun Med Res Ctr, Transplantat Res Inst, Dept Microbiol & Immunol,Xenotransplantat Res Ctr, Seoul, South Korea