ACTA1 and neoplasm: However, IHC staining showed that the expression of leptin (an adipocyte marker) and α-SMA (a fibroblast marker) was marginally induced in the HFD-fed tumor xenografts (Figure 5D and Supplemental Figure 3B), suggesting that circulating leptin may play a more vital role for the development of HFD-fed tumor xenografts.