The only reasonable explanation for the significant difference in the glucose levels after the STZ injection and during the glucose tolerance test between the TGFβ1 TG/STZ and WT/STZ groups is the increased circulating TGFβ1-associated insulin resistance, as confirmed by the significantly increased HOMA-IR in the TGFβ1 TG/STZ mice compared to the WT/STZ mice, as described in Figure 2C. These findings further support the detrimental effect of TGFβ1 overexpression on insulin sensitivity under diabetic conditions. Here, TGFB1 is linked to Insulin resistance.