NIH3T3 cells were transfected with a fixed amount (0.9 µg) of Dpp2 promoter luciferase construct and a construct expressing A) KLF2 (HA-tagged) or B) MADMYC, and C) TOB1 at varying amounts (0.25, 0.5 and 1.0 µg), normalized with empty expression vector (pCI-Neo) or 1.0 µg of empty vector alone. Lysates were analyzed for luciferase activity 48 h post transfection. An aliquot of the lysate was run on SDS-PAGE and western-blotted for HA, MYC, or TOB1 expression. KLF2 and MADMYC both increase the Dpp2 promoter activity. D) Transfection of KLF2 decreases endogenous c-Myc expression in NIH3T3 fibroblasts. c-Myc protein levels were normalized to β-actin. Data shown are mean ±SD of duplicate transfections from a single experiment, representative of three (left). Statistical differences between the groups were determined by Student’s two-tailed t-test from three experiments (right).