Several animal studies also showed that treatment with gastrin induced the formation of new β-cells under various conditions.[8–10,15] Suarez-Pinzon et al[15] further showed that the combination of epidermal growth factor and gastrin increased the number of β-cells in adult human pancreatic tissue cultured in vitro and significantly increased β-cell and insulin content in human islet cells implanted in nonobese diabetic/severe combined immunodeficiency mice. This evidence concerns the gene EGF and severe combined immunodeficiency.