Replenishing IgM in the IgM ko mice with a single 240 μg dose of polyclonal IgM, to achieve plasma levels similar to that in their WT counterparts, protected these IgM ko mice from developing AKI with mild ischemia, thus indicating that sensitivity to ischemia in the IgM ko mice resulted from a lack of circulating IgM (Figures 9A,B). The gene discussed is CD40LG; the disease is ischemia.