Concerning differential diagnosis with PRCA, FC is able to prove the absence of CD117+ and CD105+ erythroblasts in BM samples, which is a typical feature of PRCA, together with evidence of a severe reduction/absence of proerythroblasts; despite its diagnostic relevance, this approach is not currently standardized and PRCA remains a diagnosis by exclusion [63,80]. Here, ENG is linked to pure red-cell aplasia.