Effects of GKA (RO28-1675) on TGF-β mediated Smad2C phosphorylation in endothelial cells. A. Western blot of whole cell lysates from BAECS treated with TGF-β (2 ng/ml) for 5 min in the presence and absence of GKA (RO28-1675) (1-10 μM). SB431542 (3 μM) was used as a positive control. Cell lysates were resolved on SDS-PAGE and transferred onto a PVDF membrane. This membrane was probed with anti-phosphoSmad2(Ser465/467) Also reprobed for anti-Smad2 and anti-GAPDH. Chemiluminescence was used to detect the proteins of interest. B. Histogram is a densitometric quantitation of 3 Western blots.