The H&E staining of uninjured coronary artery (A, B, C) shows normal histology, whereas 16 weeks after balloon angioplasty neointimal hyperplasia (arrows) is noted in post-PTCA-coronary arteries (D, E, F). H&E staining of the uninjured SEV showed normal histology (G, H, I). SEV that was used as a graft (J, K, L) developed neointimal hyperplasia (arrows). Increased Expression of Phosphorylated Polo-Like Kinase 1 and Histone in Bypass Vein Graft and Coronary Arteries following Angioplasty: Sur S, Swier VJ, Radwan MM, Agrawal DK - PloS one (2016). Not altered. CC.