SMAD4 and colorectal cancer: Also, a significant change in AGR2 gene expression accompanied several CNV features known to drive colorectal cancers, especially those involved in cell cycle control (TP53, FBXW7, RB1, CDC27 and AURKA), in WNT signalling (APC, WNT4, FZD3 and AJUBA) and others (SMAD4 and SMAD2).