Pokharel S, Rasoul S, Roks AJ, van Leeuwen RE, van Luyn MJ, Deelman LE, Smits JF, Carretero O, van Gilst WH, Pinto YM. N-acetyl-Ser-Asp-Lys-Pro inhibits phosphorylation of Smad2 in cardiac fibroblasts. Hypertension. 2002 Aug;40(2):155–61. doi: 10.1161/01.hyp.0000025880.56816.fa. PMID: 12154106.