CD22 and acute myeloid leukemia: Thirty nine dogs were diagnosed with AML based on flow cytometric expression of myeloid-associated antigens (n = 33) or positive cytochemical staining reactions combined with negative staining for T (CD3/CD5) or B (CD21/CD22) lymphoid-associated antigens on flow cytometric analysis (n = 6) (Table 6, Supplementary Table S5).