When recombinant human IL-10 is intravenously administered in healthy volunteers, the side effects mainly consisted of mild-to-moderate flu-like symptoms which were characterized by fever with chills, headache, myalgias at the highest dose (100.0 micrograms/kg), transient decreases of lymphocyte counts, decreased platelet counts, which returned after discontinuation of the IL-10 (Huhn et al., 1996; Sosman et al., 2000). This evidence concerns the gene IL10 and Myalgia.