Programmed Cell Death 1 (PD-1) and Cytotoxic T Lymphocyte-Associated Antigen 4 (CTLA-4) in Viral Hepatitis Cho, H.; Kang, H.; Lee, H.Hee.; Kim, C.Wook. International Journal of Molecular Sciences 18(7) 2017 https://eurekamag.com/research/060/140/060140091.php