KIR3DL1 and neoplasm: Our data seem to complement these observations, suggesting that, depending on a more responsive NK cell phenotype (number of aKIRs) and specific activatory/inhibitory KIR/HLA pairs (e.g. KIR3D/HLA-Bw4), tumor response could be more or less effective, leading to a different degree of reduction in the size of primary tumors.