Sensitized control mice had profound physiological reactions to challenge as indicated by severe symptoms of anaphylactic shock, including diarrhea, labored respiration, wheezing, lack of activity when prodded, core body temperature loss of greater than 2°C, hemoconcentration and increased mast cell degranulation (MCPT-1) (Figure 1). The gene discussed is CPT1B; the disease is anaphylaxis.