['Surfactant protein-D (SP-D) is a primordial component of the innate immune system intrinsically linked to metabolic pathways. We aimed to study the association of single nucleotide polymorphisms (SNPs) affecting SP-D with insulin resistance and type 2 diabetes (T2D).', 'We evaluated a common genetic variant located in the SP-D coding region (rs721917, Met(31)Thr) in a sample of T2D patients and non-diabetic controls (n\u200a=\u200a2,711). In a subset of subjects (n\u200a=\u200a1,062), this SNP was analyzed in association with circulating SP-D concentrations, insulin resistance, and T2D. This SNP and others were also screened in the publicly available Genome Wide Association (GWA) database of the Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC).', 'We found the significant association of rs721917 with circulating SP-D, parameters of insulin resistance and T2D. Indeed, G carriers showed decreased circulating SP-D (p\u200a=\u200a0.004), decreased fasting glucose (p\u200a=\u200a0.0002), glycated hemoglobin (p\u200a=\u200a0.0005), and 33% (p\u200a=\u200a0.002) lower prevalence of T2D, estimated under a dominant model, especially among women. Interestingly, these differences remained significant after controlling for origin, age, gender, and circulating SP-D. Moreover, this SNP and others within the SP-D genomic region (i.e. rs10887344) were significantly associated with quantitative measures of glucose homeostasis, insulin sensitivity, and T2D, according to GWAS datasets from MAGIC.'] Are common genetic variants of surfactant protein-D ( SP-D ) associated with type 2 diabetes?