Systemic (intraperitoneal) challenge of sensitized C3H mice with OVA resulted in anaphylaxis in most mice, and responders showed elevated levels of OVA-specific IgE (Fig 4D), IgG1 (Fig 4E), IgG2a (Fig 4F), MMCP-7 (Fig 4C) and histamine levels (not shown). Here, IGHE is linked to anaphylaxis.