CD2 and acute myeloid leukemia: When compared to normal/reactive mature pDCs, the major immunophenotypic differences observed in pDCs of pDC-AML include altered (increased or decreased) expression of normal pDC markers, such as CD2, CD4, CD7, CD22, CD33, CD34, CD36 and TCL1, or expression of myeloid antigens such as CD117 and CD13.