unswitched memory B cell CD38-positive unswitched memory B cell A CD38-positive unswitched memory B cell is an unswitched memory B cell that has the phenotype CD38-positive, IgD-positive, CD138-negative, and IgG-negative. CD38-positive unswitched memory B-cell CD38+ unswitched memory B cell CD38+ unswitched memory B lymphocyte CD38-positive unswitched memory B lymphocyte CD38+ unswitched memory B-cell CD38+ unswitched memory B-lymphocyte CD38-positive unswitched memory B-lymphocyte