Previous studies showed that CA has a lowering effect on postchallenge plasma glucose levels in humans in vivo9, through enhancing glucose uptake, facilitating glucose transporter isoform 4 translocation and inhibiting the enzymatic activities of several diabetes-related non-receptor protein tyrosine phosphatases, such as PTP1B, T-cell-PTP, src homology phosphatase-1 and src homology phosphatase-247. The gene discussed is PTPN1; the disease is diabetes mellitus.