KLRB1 and hepatocellular carcinoma: Moreover, through meticulous comparison of KLRB1 expression levels on T cells and NK cells among HCC patients with divergent prognostic outcomes, our findings underscore a significant reduction in KLRB1 expression on CD8+ T and NK cells among patients experiencing recurrence or mortality, in stark contrast to those with favorable prognoses (Fig. 3; Table 2).