Identification of critical elements within the endoglin promoter. A set of deletion constructs were generated and inserted into a reporter vector containing the luciferase gene. BAEC were transiently transfected with the indicated promoter constructs and luciferase activity was determined 48 hours after transfection. Correction for transfection efficiency was made by cotransfection with β-galactosidase expression vectors and parallel transfections with the pGL2-SV40 and pXP2 vectors. This is a representative experiment of four separate experiments.