CD80 and hematopoietic and lymphoid cell neoplasm: Flow cytometric analysis of CD86 expression on canine hematopoietic neoplasms has not been performed to our knowledge but immunohistochemical staining with CD86 (clone CA24.3E4) yielded discrepant results (positive and negative) of histiocytic tumors in 2 dogs, both of which were also positive for CD80 (44, 45).