A few studies have suggested that specific IgG antibodies against hexamethylene diisocyanate (HDI)-HSA and methylene diphenyl diisocyanate (MDI)-HSA conjugates play a pathogenic role in occupational asthma based on an association between IgG antibodies and the results of bronchoprovocation tests (BPTs), [21] whereas other investigators have suggested that specific IgG antibodies against MDI are merely indicators of MDI exposure [22]. The gene discussed is ALB; the disease is occupational asthma.