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(2008) Structural and functional constraints limit options for cytotoxic T-lymphocyte escape in the immunodominant HLA-B27-restricted epitope in human immunodeficiency virus type 1 capsid. J Virol 82: 5594–5605. PLoS ONE | www.plosone.org 12 August 2009 | Volume 4 | Issue 8 | e6687