Thus, despite development of high parasitemia levels by B. microti, combined anti-inflammatory response promoted by IL-10 and Tregs could partially explain why this infection does not result in death of mice unlike infection with Babesia strain WA-1, which displays fatal outcomes that showed association with the high levels of IFN-γ and TNF-α production in spleen and lungs, heavy intravascular hemolysis, and multiorgan failure (101–103). The gene discussed is TNF; the disease is parasitic infectious disease.