New research has examined the usefulness of bone marrow stem cells for treating male infertility, with promising results. The related report by Lue et al, “Fate of bone marrow stem cells transplanted into the testis: potential implication for men with testicular failure,” appears in the March issue of The American Journal of Pathology. When a couple experiences infertility, the man is just as likely as the woman to be the cause. Male infertility may arise from failed proliferation and differentiation of the germ cells (precursors of sperm) or from dysfunction of the supporting cells. New research is looking to stem...