ITGAL and hyperinsulinemic hypoglycemia, familial, 4: In an early study using T cells derived from leukocyte adhesion deficient (LAD) patients with genetic defects in β2 showed a decreased expression of LFA-1 and LFA-1 LAD derived T cells still bound to endothelial cells similar to normal T cells via complementary binding through VLA-4, but their transmigration through the endothelial layer of LAD derived T cells was significantly decreased (206).