Despite Syk deficiency at the initiation of HDM sensitization, the 8-week exposure elicited peripheral leukocytosis in both the Sykdel/del and Sykflox/flox mice, and was accompanied by significant increases in the total numbers of neutrophils, lymphocytes and eosinophils (Fig 4A–4D; * p <0.05, Saline vs. HDM, n = 4/group). The gene discussed is SYK; the disease is Increased total leukocyte count.