TGFβ signaling is abnormally elevated in the absence of LRP1 in vivo, where analysis of SMC-specific LRP1 knockout (smLRP1−/−) mice revealed a Marfan syndrome-like phenotype with nuclear accumulation of phosphorylated Smad2 (p-Smad2) and disruption of elastic layers in the vessel wall [15]. Here, TGFB1 is linked to Marfan syndrome.