It is difficult to extrapolate to protein expression and whether it is greater in mouse than man or vice versa, but the levels of nonesterified 25-HC in mouse and human plasma are not drastically different at about 1 and 1–5 ng/ml, respectively (31, 113, 132, 166), which would imply that at least in the absence of infection, CH25H protein levels are quite similar. The gene discussed is CH25H; the disease is infection.