B3GAT1 and cancer: Our data suggest that proportions of CD57+ and KIR+ NK cells in the periphery are in part genetically determined, and that in the case of KIR positivity, this is associated with large-scale transcriptional changes in trans. A complete understanding of NK cell phenotypes as a predictor of cancer predisposition or outcome needs to reflect genetically determined inter-individual differences in NK cell phenotype at baseline.