The gating strategy for identifying naive B-cells (CD20+IgD+CD27−), class-switched memory B-cells (CD20+IgD−CD27+), and plasmablasts (CD20+IgD−CD27+CD38+), as well as CD73 expression on different B-cell subsets, are demonstrated in Figure 2A. We found that the majority of CD73-expressing B-cells was allocated to class-switched memory B-cells in both tumor and blood samples, followed by naive B-cells; nevertheless, it seemed that plasmablasts expressed no CD73 at all (Figure 2A,B). Here, CD27 is linked to neoplasm.