ITGB2 and leukocyte adhesion deficiency: The deficiency of the β2 integrin subunit of the LFA-1 causes the leukocyte adhesion deficiency (LAD) type I, and the defective activation of LFA-1 subunits has been related to the LAD type III, both nowadays effectively treated with the hematopoietic stem cells transplantation (44, 45).