Coding variants identified in T2D-GWAS include the protective missense (Q325W) and nonsense (R138*) mutations in SLC30A8 [222], and other low frequency (<5%) or rare (<0.5%) coding mutations identified by exome sequencing in genes such as TBC1D30, KANK1, PAM or PPIP5K2, which have been associated with altered insulin processing and secretion [190] or a CCND2 coding variant associated with increased expression, and T2D-risk reduction by half [9], among many others [264]. Here, CCND2 is linked to type 2 diabetes mellitus.