Using chromatin immunoprecipitation on BM LDCs isolated from two MF patients we found that, like in CLL cells [15], STAT3 co-immunoprecipitated DNA of all analyzed fragments, indicating that STAT3 binds the GLI1 gene promoter in MF fibrocyte-forming cells (Fig. 7B). Here, STAT3 is linked to B-cell chronic lymphocytic leukemia.