PHGDH and lung adenocarcinoma: In particular, the high-PHGDH-mediated activation of SSP supports sorafenib resistance in hepatocellular carcinoma by sustaining enhanced antioxidant response [52]; similarly, PHGDH levels are significantly increased in lung adenocarcinoma that acquires resistance to erlotinib, regulating cellular redox balance and supporting adaptive response to counteract drug treatment [53].