SMAD4 and neoplasm: The TGF-β pathway was deregulated by alterations to TGFBR1, TGFBR2, ACVR2A, ACVR1B, SMAD2, SMAD3 and SMAD4 in 27 % of non-hypermutated MSS tumours and 87 % of hypermutated cancers.