A large number of white blood cell diseases are characterized by the overexpression and activation of LFA-1 such as certain hematologic malignancies and autoimmune/inflammatory diseases, including inflammatory bowel disease (Crohn’s disease and ulcerative colitis), rheumatoid arthritis, psoriasis, multiple sclerosis, type I diabetes, allergic asthma, and dry-eye disease [30,31,32,33,34,35,36,37]. Here, ITGB2 is linked to Crohn disease.