Role of host and viral genotype on susceptibility to IM and EBV⁺ PTLD. The development of IM depends on the host HLA-E allele and HLA-E–restricted CD8⁺ T-cell response. EBV⁺ PTLD are associated with the HLA-E/LMP-1/NKG2A axis and depend on specific EBV and host genetic variations involved in this pathway. Professional illustration by Somersault18:24.