PDCD1 and hepatocellular carcinoma: Several studies across various malignancies have indicated that systemic immune activation, particularly the proliferation and functional restoration of CD8+ T cells in the peripheral blood, is associated with a favorable response to PD-1 inhibitor therapy.15–18 However, a specific and readily measurable immune subset predictive of response to the complex triple combination of lenvatinib, TACE, and PD-1 inhibitors (LEN-TAP) in HCC patients remains to be identified.