SMAD2 and liver cancer: To gain mechanistic insights into the effects of DYRK1A on activating TGF-β/SMAD signalling and promoting metastasis, the proteins interacting with DYRK1A were analysed using mass spectrometry; in addition, genes coexpressed with DYRK1A, SMAD2 and SMAD3 in liver cancer were identified with the UALCAN platform as those with Pearson correlation coefficient (r) values greater than 0.5 (Additional file 10: Table S5) [19, 28].