CD34 and myelodysplastic syndrome: One hallmark of +8 MDS is that the chromosomal aberration is thought to occur late during disease pathogenesis, as evidenced by its detection in myeloid progenitors and near absence in CD34+ stem cells   34 .+8 MDS cells express high levels of anti-apoptotic proteins (such as survivin) and exhibit strong resistance to apoptotic stimuli (such as gamma ray irradiation or withdrawal of growth factors)   35 .