Reduced smooth muscle differentiation and transforming growth factor β2 (TGFβ2) signaling in neural crest cell (NCC)-specific integrin-linked kinase (ILK) knockout (NKO) mutant outflow tract (OFT). (A-B’) Reduced expression of α-smooth muscle actin (αSMA) in NKO mutant aortic arch (aa) that is derived from NCCs (tdTomato+) (B,B’, arrow) at E12.5. Smooth muscle differentiation from non-neural crest (tdTomato-) appears to be normal (B,B’, arrowhead) (es esophagus, scg superior cervical ganglia, tr trachea). (C-D) Reduced TGFβ2 expression in E9.5 NKO mutant OFT (arrow) revealed by wholemount in situ hybridization. (E) Western blot using ILKf/f;Cre+ mutant and control NCCs with antibodies to TGFβ2 and total Smad2 and phosphorylated Smad2. (E') quantitative assessment of western blot results (E) showing reduced TGFβ2 expression and Smad2 phosphorylation.