It has recently been claimed that following infection of A/J mice with the coronavirus murine hepatitis virus strain 1 (MHV-1), responsible for the development of an acute SARS-like disease in susceptible mice (severe acute respiratory syndrome), caused an increase in SF2/ASF and full length CD200 (at the expense of CD200tr) and may be associated with in the increased susceptibility of A/J mice (over the resistant BL/6 counterpart) to disease [28]. This evidence concerns the gene CD200 and infection.