KLRD1 and graft versus host disease: For patients with an HLA-mismatched graft, there is a trend that the proportions of CD94/NKG2A-positive NK cells increase from about 60% to 75% after two months of alloSCT in patients with acute (n = 5) and chronic GvHD (n = 3) and they maintain this level over a time period of six months, whereas in patients with no or only mild acute/chronic GvHD the proportions of this type of NK cell decrease from about 70% to 55%.