Ultimately, however, in vivo studies will be needed and while viable MOSPD2 knockout mice have been reported (54), discriminating between direct and indirect effects of such a disruption will be extremely difficult; i.e., determining whether any difference in the course of an infection with Toxoplasma in such animals is because of a specific role of MOSPD2 at the PVM or is due to a generalized effect on the host’s overall metabolism, immunity or other characteristic. The gene discussed is MOSPD2; the disease is infection.