Although variable results were observed for individual cases, follow-up studies performed in a group of 11 MDS patients showed a tendency towards decreased PI of non-lymphoid CD34+ cells –from 5% (0–17%) to 0.9% (0–14%); p = 0.06-, CD11b− neutrophil precursors –from 30% (8–38%) to 16% (4–28%); p = 0.02- and NRBC –from 28% (9–32%) to 19% (7–30%); p = 0.05- vs. those found at diagnosis; such tendency was observed not only among cases which showed more advanced disease but also among cases which had the same WHO diagnosis after follow-up (n = 5, data not shown). Here, CD34 is linked to myelodysplastic syndrome.