RB1 and chronic myelomonocytic leukemia: Reduced expression of H19 Imprinted Maternally Expressed Transcript has been observed in chronic myeloid leukemia (CML), and myelomonocytic leukemia (CMML), as well as in AML [47], and is also the precursor of miR-675 known to downregulate the retinoblastoma (RB) gene, a fact that multiplies the level of complexity to its functional roles [55].