CTLA4 and Vogt-Koyanagi-Harada disease: Recent studies have shown that polymorphisms of several immune related genes such as cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) [13],interleukin (IL)–17 [14], signal transducers and activators of transcription 4 (STAT4) [15] and osteopontin (OPN) [16] are associated with susceptibility to VKH disease.