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). The gene discussed is SMAD4; the disease is acute myeloid leukemia.