GCG and type 1 diabetes mellitus: In conclusion, our study indicates that the metabolic alterations induced by IRKD in α-cells, especially the increase of taurine, may lead to a distorted glucagon response in IRKD αTC1-6 cells, i.e., an in vitro model of insulin-deficient α-cells, thus suggesting the importance of taurine in the paradoxical glucagon response and the resultant glucose instability in insulin-deficient type 1 diabetes.