To analyze activation status of splenic B cells post-infection, flow cytometry was performed to measure surface expression of CD69, CD86, CD95 (Fas) and CD95L (FasL) at days 8, 15, and 28 post-inoculation, comparing expression on B cells in infected mice to control mice receiving heat-inactivated parasite (Fig 6). The gene discussed is FASLG; the disease is infection.