In marrow transplantation, the word "match" refers to how similar the HLA typing is between the donor and the recipient. The best kind of match is an "identical match". This means that all six of the HLA antigens are the same between the donor and the recipient. This type of match is described as a "6 of 6 match". Donors and recipients who are "mismatched" one antigen are considered a "5 of 6 match", and may be considered suitable for marrow transplantation.