BACH1 and carcinoid tumor: Western blot analysis showed an increase in cellular content of the HMGA2, BACH1 and MMP1 proteins (we assume that the modest increase seen in MMP1 in comparison to BACH1, might be due to other regulatory processes in the different tissues and cell lines than that of BACH1) when a let-7 family inhibitor was transfected into the carcinoid cell lines confirming the two proteins as genuine targets of let-7 (Figure 5c,d).