Similarly, in triple-negative breast cancer (TNBC), PCK2 modulates Smad3 expression and phosphorylation by inhibiting TRIM67-mediated Smad3 ubiquitination; this action consequently enhances TGF-β-stimulated Smad3 activity and activates TGF-β/Smad3 signalling (116). Here, SMAD3 is linked to triple-negative breast carcinoma.