KIR3DL1 and cytomegalovirus infection: Together, the data suggest that CMV infection in immunosuppressed PTLD patients drives NK cells to terminally differentiated NKG2ChiCD57+NKG2A−KIR+ NK cell subset as described in other settings and might impair the generation and maintenance of EBV-reactive CD56dimNKG2A+KIR− NK cells.