We note that the variant at the TP53INP1 locus on chromosome 8 (rs896854, lying in intron 1) associated with T2D in GWAS studies (Voight et al, 2010) appears to lead to impaired β-cell function (i.e. reduced insulin secretion), as measured by a decrease in HOMA-B (Voight et al, 2010) and unchanged insulin sensitivity. The gene discussed is TP53INP1; the disease is type 2 diabetes mellitus.