EBV infected of B cells and T cells, leading to infected B cells infiltrated of the CNS and T cell exhaustion, where CD8 T cell deficiency contributed to the decreased CD8 T cell response to EBV-infected B cells and with functional declined in aged MS patients (Pender et al., 2012; Soldan and Lieberman, 2023). Here, CD8A is linked to myeloid sarcoma.