In T1D, in contrast to the rightward shift in the dose–response curves for EGP as a function of peripheral insulin levels, these curves have been found leftward shifted when expressed as a function of portal insulin concentrations compared with healthy individuals; this was due to the rightward shift of the control curve when expressed as a function of calculated portal insulin levels which were higher than peripheral (24). The gene discussed is INS; the disease is type 1 diabetes mellitus.