Fig. 3. In vivo DMS footprinting of the human c-FMS promoter reveals significant protections over the PU.1 and AML-1 sites previously identified with in vitro assays (Zhang et al., 1994). c-FMS non-expressing cells have similar DMS reactivity compared with naked DNA. Both undifferentiated and PMA-differentiated HL60 cells show similar occupancy to primary macrophages, with Kasumi-1 cells and CD34⁺ blast cells from leukaemia patients (P2 and P9) showing weaker footprints. The lower panel shows the promoter sequence, with protections from DMS reactivity indicated as white circles. G, G reaction with naked DNA.