This correlates with our observation, that PTP1B knockdown protects podocytes from ER stress, but other, apparently unrelated PTP1B activities, such as its role in the downregulation of VEGF signalling32, make the possibility of PTP1B as a good therapeutic drug target for the prevention of ER stress, podocyte injury and the development of DN more complicated. This evidence concerns the gene PTPN1 and liver dysplastic nodule.