SMAD2 and colorectal carcinoma: Multiplex immunohistochemistry performed on CRC tissue microarrays revealed increased expression of TGF-β1, TGFBRI, TGFBRII, SMAD4, SMAD2/3, SMAD1/5/9, and phosphorylated SMAD2/3 in tumor tissue compared to adjacent mucosa [66,67].