When the iMADs were co-infected with Ad-BMP9, Ad-GFP, Ad-simRmst, and/or Ad-NICD1, we found that exogenous expression of NICD1 effectively prevented the decrease in ALP activity caused by Rmst silencing; and in fact significantly increased ALP activity determined at 3, 5 and 7 days after infection (Figure 7A). Here, GDF2 is linked to infection.