CD4 and infection: Interestingly, four (NS4b 1791-1806, NS4b 1918-1933, NS5b 2946-2963, NS5b2965-2975) of these identified as CD8 T cell epitopes overlap with CD4 T cell epitopes in the non-identical but equivalent genotype-1a viral regions.29, 31, 38, 39 Only in one epitope was the genotype-3a viral sequence identical to that found in genotype-1a infection.