CD34 and acute myeloid leukemia: RXFP1 expression is markedly elevated in leukemia cells, with 2.71-fold increases in acute myeloid leukemia (AML) and 3.31-fold increases in chronic myeloid leukemia (CML) compared with control populations (CD34+/CD38- stem cells and CD34+/CD38+ progenitor cells) [32].