Notably, patients with atypical EBV reactivation (concurrent anti-EBNA1 IgG and IgM positivity) displayed both elevated dsRNA and cytokine levels (GM-CSF, IFN-γ, IFN-λ1/2/3, IFN-α2, and IL-12p70), suggesting that elevated dsRNA levels could be triggering secretion of antiviral cytokines during EBV reactivation in early MS. Here, IFNL1 is linked to myeloid sarcoma.