CD22 and leukemia: A B cell lineage was confirmed for 1 dog with a CD21−/CD22+ lymphoma/leukemia in the bone marrow on the basis of a clonal B cell population on polymerase testing for antigen receptor rearrangements (PARR) and CD20+/CD3− cells on immunocytochemical staining of bone marrow smears (Supplementary Table S3).