CD4 and hepatocellular carcinoma: Patients with an increased T-effector/Treg ratio before treatment showed significant improvement in OS. ERK + FLT-3+ Treg and MDSCs were significantly reduced after sorafenib treatment. An increase in baseline Flt-3+ p-ERK + MDSC was associated with a patient survival benefit. Conclusion High baseline CD4+ T effector/Treg ratio may be an important biomarker for prognosis in HCC.