Inhibition of BMP2 induced Smad1/5/8 phosphorylation by secreted HJV. HepG2 cells were serum-starved for 1 day, preincubated with condition medium (CM) collected from HEK293 cells transfected with indicated plasmids, and then treated with BMP2 (100 ng/mL) for various times (A). CM containing secreted HJV or HJVΔGPI mutant was revealed by Western blot analysis (B). BMP2-induced Smad1/5/8 phosphorylation in HepG2 cells was analyzed by Western blot analysis as shown in panel C. (D) Quantification analysis of data from panel C. Data were quantified by National Institutes of Health ImageJ program from 3 different experiments. Means ± SD are presented.