Study design. BALB/c mice were epicutaneously (EC) immunized for 2 weeks with OVA alone or OVA plus CpG or CpG alone or PBS. A, After a 1-week interval, all animals were challenged with OVA for 1 week before bleeding and skin sample collection. B, Reduction of OVA-specific IgE production in mice EC immunized with OVA and CpG. C, Increase of OVA-specific IgG2a secretion in mice EC immunized with OVA plus CpG. D, Inhibition of EPO activity in skin homogenates from mice EC immunized with OVA and CpG. Fig 1, B and C, n = 3–5; Fig 1, D, n = 8–20. ns, Not significant. *P < .05, **P < .01, and ***P < .001.