deCODE discovered the link between type 2 diabetes (T2D) and variants in the TCF7L2 gene, the most important common known genetic risk factor known, and variants in the CDKAL1 and other genes linked to insulin response and both increased and decreasednT2D risk. The deCODE team has made contributions to the understanding of genetic variation influencing a range of other diseases and traits including glaucoma; menarche; essential tremor; tuberculosis susceptibility; height; gene expression; hair, eye and skin pigmentation; aortic valve stenosis; rhinosinusitis; and dozens of others.