PHGDH and hepatocellular carcinoma: PRMT1-mediated methylation activates PHGDH in HCC [45, 46] and drives resistance in TNBC [20]; p38-dependent phosphorylation at S371 triggers nuclear translocation during glucose restriction [11]; and AMPK-mediated phosphorylation at S55 redirects flux toward malate oxidation, generating nuclear NADH to support epigenetic remodeling [11].