The previously reported evidence that drug clearance was significantly increased in patients with untreated type I diabetes, an effect that was reversed by insulin treatment13, 14, coupled with evidence from the mouse model of diabetes in which mice exhibited increased basal expression of CYP enzyme that was corrected by insulin administration15, prompted us to assess the direct regulation of PXR by glucose in vitro. The gene discussed is PPIG; the disease is type 1 diabetes mellitus.