Thus, inadequate levels of insulin are importantly the result of deficiency in either \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\beta $$\end{document}β-cell mass or function, or both, leading to hyperglycemia and diabetes. The gene discussed is INS; the disease is diabetes mellitus.