Additionally, the oxidative stress-responsive kinase 1 (OSR1), upregulated in both human BC samples and cell lines, phosphorylates both the linker region of SMAD2 at Thr220 and the SMAD3 linker region at Thr179; pSMAD2/3 translocates into the nucleus to enhance TGF-β pathway signaling, increasing the transcription of EMT regulators and promoting BC metastasis [170]. Here, SMAD3 is linked to breast cancer.