HEY1 and adenocarcinoma: However, we could not observe such an induction of Hey1, Hey2 or Id2 in primary human vascular smooth muscle cells from the umbilical artery, HEK293, HeLa or A549 adenocarcinoma cells (Fig. 5).This indicates that endothelial cells react much stronger to BMPs in the serum than other cell types and cell lines.