May-Grünwald-Giemsa staining of peripheral blood smears (Figure 1D, upper panels), myeloperoxidase staining of spleen imprints (Figure 1D, lower panels) and flow cytometric analyses of Gr1 and Mac1 expression (Figure 1E) showed the typical morphology and myeloid markers expression patterns of PR and AE leukemia. Here, MPO is linked to leukemia.