INSR and hyperinsulinism: Interestingly, there was a significant increase in internalization in MDC-treated hyperinsulinemic cells as compared to MDC-treated naïve cells following acute insulin stimulation (p = 0.0420, 24.86% difference; Figure 3A,B), suggesting that clathrin-mediated endocytosis is not utilized for insulin receptor internalization in conditions of hyperinsulinemia.