tokens: The pDDm - TO harboring p53 dominant negative form ( p53DD ) pGL3 - E1bTATA and the pE1B - hWAF1 firefly luciferase reporter containing the p53 - responsive element of the p21 / WAF1 promoter were described previously ( 16 , 17 ) pE1B - BAXi contains the p53RE identified in the intron 1 of the BAX gene [ ( 18 ) and D . Munsch , personal communication ] .