Mouse embryonic fibroblast (MEF) of AIMP1-knockout mice reportedly exhibit increased phosphorylation of Smad2 and Smad3, and knockdown of AIMP1 using short-interfering RNA (siRNA) promotes phosphorylation of Smad2 in human lung adenocarcinoma A549 cells.22 This evidence concerns the gene AIMP1 and lung adenocarcinoma.