ENPP1 and type 2 diabetes mellitus: For example, microarray studies performed on human pancreatic islets isolated from patients with type 2 diabetes and glucose-tolerant controls identified, among other changes, overexpression of ENPP1, TSPAN4, TSPAN8, CSRP1, REG3A and REG3G [29, 30], genes that were also upregulated with age in our study.