Summing up, in Crohn’s disease sufferers, perianal disease, complicated disease type, ileocecal disease, hypoproteinemia, high PCDAI at diagnosis, elevated total serum IgA, and, marginally, anemia and L4a and L4b coexistence, turned out to be predictors of biologic therapy adoption before the age of 18 years. The gene discussed is CD79A; the disease is anemia.