In 2009, a previous retrospective Italian analysis, performed on 805 couples, reported that globally there are no differences in terms of outcomes (Overall Survival, Disease Free Survival, Relapse Rate and Transplant Related Mortality and Graft Versus Host Disease) in adult patients with neoplastic diseases transplanted with HLA-matched donor 10/10 or 9/10. However, stratifying patients by stage of disease at transplant, a single HLA incompatibility significantly increases the risk of mortality in patients who received HSCT in early stage whereas this data is not confirmed for patients transplanted in advanced stage of disease. This previous Italian analysis included only 10/10 high-resolution typed pairs from 1999 to 2006, excluding all the others couple without a full HLA typing for avoiding confounding results. According to Italian Bone Marrow Donor Registry standard, extended HR HLA was not a mandatory requirement from 1999 to 2006.