LAP expression on circulating granulocytes from control subjects, from patients with myeloproliferative disorders without JAK2 (V617F) mutant alleles, and from patients with myeloproliferative disorders carrying the mutation. Control subjects include healthy individuals and patients with reactive conditions. LAP expression levels are shown in a box plot where circles indicate outliers. The Kruskal-Wallis test showed significant differences between these groups (P < .001).