KLRC1 and graft versus host disease: Our prospective study on the monitoring of NKG2A and NKG2C receptor expression during the first year after alloSCT revealed (i) that, overall, the course of NKG2A and NKG2C receptor expression after alloSCT corresponds to the described phenotypical alteration of NK cell maturation [2,3,4,5]; (ii) that patients with no or mild GvHD and patients with severe GvHD display different proportions of NK cells expressing these receptors; (iii) that the association of the expression of these receptors with GvHD seems to differ with respect to the HLA-matched or HLA-mismatched allograft situation.