SMAD3 and gastric cancer: Specifically, tRF-3019a was found to promote the migration of gastric cancer cells via targeting tumour suppressors, while tRF-17-79MP9PP inhibited the migration of breast cancer cells via regulating the thrombospondin 1 (THBS1)-mediated transforming growth factor beta 1 (TGF-β1)/SMAD family member 3 (smad3) signalling pathway (133, 134).