COL1A1 and acute myeloid leukemia: Although the CM of TGF-β1-induced AML-12 cells activated the expression of α-SMA and Col1a1 in HSCs, the CM of TGF-β1-induced AML-12 cells with Smad4 knockdown significantly attenuated the expression of α-SMA in HSCs, which was consistent with the results of Western blotting analysis (Figure 6C).