A difference in the plasma BDNF concentrations of the control subjects was observed when the asthma patients and healthy individuals were subdivided according to BDNF Val66Met genotype; healthy carriers of the AG genotype were found to have nominally lower BDNF concentrations (p = 0.03) than healthy carriers of the GG genotype (Table 3). The gene discussed is BDNF; the disease is asthma.