Fig. 6. DN Lck does not inhibit SCF-stimulated growth. H526-IC4 cells containing the "reverse" Tet repressor and the empty pTRE vector or vectors encoding WT Lck or DN Lck were induced with doxycycline for 24 h, made quiescent in serum-free medium (containing doxycycline) overnight, and then left either unstimulated () or stimulated with 100 ng/ml SCF ({blacksquare}). Growth was assessed by MTT assay after 72 h. Error bars, the SD from the mean of eight replicate wells; results are representative of three replicate experiments.