TGFB1 and peripheral arterial disease: PAD-IV gastrocnemius had approximately 2.5- and 8-fold greater expression of TGF-β1 compared to PAD-II and CTRL patients (6.56 ± 3.12 vs. 2.89 ± 2.12 and 0.842 ± 0.399 gsu, respectively; both p < 0.001), while PAD-II had 3.5-fold more TGF-β1 than CTRL (p < 0.05; Fig. 2b).