Iam working with the expression of Fgf 23 in osteoblast and cDMP1. invivo published results prove that cDMP1 inhibits Fgf23. But when I studied the promoter activity of fgf23 invitro using cDMP1 by duel luciferase assay, I see that it increases the promoter activity of Fgf 23 rather than inhibiting it, which is directly contrast to what is reported in vivo. what could be the reasons for this. Im confused.