EXOC4 and type 2 diabetes mellitus: However, some of these variably erased CGIs (VECs) remained methylated at all stages, including in mature oocytes and sperm (Figure S5A), for example a CGI in the Exoc4 gene which is associated with type 2 diabetes and involved in insulin-stimulated glucose transport (Inoue et al., 2003) (Figure 4C).