By immunoblot analysis, sera from LAD patients showed IgA reactivity against keratinocyte-derived LAD-1 in 48%-50% and IgG reactivity in 24% of cases, whereas sera from BP patients had IgG against LAD-1 in 74% and IgA in 30% of cases (Figures 1A,B) (55, 85, 86). This evidence concerns the gene LAD1 and leukocyte adhesion deficiency.