In marked contrast with Cdk2, which is not considered essential on the basis of non-lethality in the mouse model [75], the metabolic enzyme ATIC, an important node in the T2D disease module [22,86], is an example of a highly conserved enzyme present in prokaryotes but not considered essential in terms of lethality in the mouse model [81]. Here, CDK2 is linked to type 2 diabetes mellitus.