Third, although mechanistic studies support the integrated OAA tautomerase and decarboxylase activities of FAHD1, wherein tautomerism facilitates efficient decarboxylation to yield pyruvate and mitigates enol-OAA-mediated SDH inhibition, their roles in inhibiting PC and enabling the PEP-pyruvate-OAA axis in HCC cells require confirmation through direct flux measurements and enzyme kinetics assays. The gene discussed is FAHD1; the disease is hepatocellular carcinoma.