we have found that a 3.7-kilobase rna homologous to the sis gene is expressed at moderate levels in cultured human and bovine endothelial cells , at low levels in in vivo endothelium from human umbilical vein , and at very low levels in bovine aortic endothelium in vivo .
C0225336
endothelial cells
C0014257
endothelium