Using a combination of KIR copy number typing and SNP imputation of KIR copy number, Pontikos et al.5 report no association of 3DL1/3DS1 with T1D in a large case–control study; however, cases were not stratified by HLA, and age of onset for all subjects was less than 17. This evidence concerns the gene KIR3DL1 and type 1 diabetes mellitus.