In contrast to the B6.Nramp transgenic mice, infection of 129X1/SvJ mice (which also express a functional Nramp1 gene) with 2 × 102 ST results in 100% survival of infected mice (Fig. S1E), and the mice harbor a chronic infection that is detectable for prolonged periods (Fig. S1F). The gene discussed is SLC11A1; the disease is infection.