GZMA and infection: This suggests that the cytotoxicity signature at 3–4 years is primarily driven by GZMA. Furthermore, at 3–4 years post infection, a greater proportion of cells in the cytotoxic cluster were found in S166–180-specific T cells (CTL, χ2 = 20.007, p = 4.52 × 10−5 [Fig. 6f]), with 11.02% of cells being cytotoxic T cells, compared to 3.4% for S751–765 and 5.68% for S866–880.