Figure 1. Vascular function of CEACAM1 during lifetime. Early in life, moderate endothelial expression of CEACAM1 contributes to vessel maturation, i.e. establishment of the endothelial barrier by promoting adherens junction formation. Thereafter, in quiescent vessels CEACAM1 expression is almost completely downregulated. However, during vascular aging, a remarkable re-expression of CEACAM1 critically contributes to upregulation of proinflammatory TNF-α, to endothelial barrier impairment and vascular collagen deposition.