Several studies have demonstrated a link between NKC locus haplotypes and NK cell responses in cancer and most studies have presumed that these effects are related to the gene encoding NKG2D.18 23 24 27 28 However, there are additional genes in this locus that affect NK cell function, such as KLRC1, KLRC2 and KLRD2, which encode NKG2A, NKG2C and CD94, respectively. Here, KLRD1 is linked to cancer.