IFNA1 and severe acute respiratory syndrome: However, elevated levels of IL-10 were also detected in some SARS patients, and this was attributed to the dual effect of IL-10 on T lymphocytes, whereby it inhibits the production of IL-2, IFN, and TNF from Th1 and activates cytotoxic CD8+ T cells and NKs, hence increasing susceptibility to the disease [94].