The neutralizing effect of the mouse anti-RipE antiserum for reducing E. japonica infection in vitro was similar to that of anti-rP28 (Figure 10), which can neutralize E. chaffeensis infection in immunocompetent mice (Ohashi et al., 1998) and protect severe combined immunodeficiency mice from fatal E. chaffeensis infection (Li et al., 2001). The gene discussed is FAM161A; the disease is immunodeficiency disease.