In aggressive murine HCC (HCC/CAMIN), we detected several B cell populations, such as CD19-B220+CD5+CD1d- Bregs, CD19+B220+CD5+CD1d+ B10 Bregs, CD19+B220+CD27+IgD+ NSw MBCs, and CD19+B220+CD138+ PBs, which all demonstrated a protumorigenic phenotype (upregulated IL-10 and PD-L1). Here, IL10 is linked to hepatocellular carcinoma.