CD27 and agammaglobulinemia: Moreover, basic humoral immunologic assays (hypogammaglobulinemia, increased percentage of CD38+IgM+ transitional B cells and CD27− naive B cells, and a diminished IgM−IgD−CD27+ class-switched memory B cells) have been identified in the previous report of these CD70-deficient patients (22), resembling B-cell phenotype that is most similar to CVID patients who are classified as B+smB−Trhi according to the EURO classification (41).