Even though the role of Breg cells (defined as: CD24hiCD38+CD1d+CD5+) in the antitumor defense has not yet been fully uncovered, we could measure a significant difference in circulating Bregs in HCC patients compared to HD (HCC patients: 0.32 ± 0.26% vs. HD: 1.65 ± 0.5%; p = 0.014) (Fig. 1c, Fig. 3 and supplementary Fig. 2). This evidence concerns the gene CD5 and hepatocellular carcinoma.