Deletion constructs of the LMO2 distal promoter assayed in K562 and COS cells. The gray boxes indicate the K562 data, the black boxes are the expressed level in COS cells. The values were normalized for transfection efficiencies using a cotransfected β-galactosidase construct. The longest construct recapitulates expression of the endogenous gene. Moreover, the level of the reporter gene activity is maintained in the erythroid cells throughout the deletion series.