TCF7L2 and type 1 diabetes mellitus: Finally, the comparisons between T2D and T1D reveal the repression of important genes associated with T2D diabetes, particularly transcription factors involved in glucose homeostasis (TCF7L2) [24,48], NAD + (FOXO3) [49] and regulation of cellular and systemic response to hypoxia (HIF1A) [50], and the differential expression of HIF1A and FOXO3A in our series was also confirmed by real-time PCR.