B-2 B cell follicular B cell Fo B cell follicular B-cell A resting mature B cell that has the phenotype IgM-positive, IgD-positive, CD23-positive and CD21-positive, and found in the B cell follicles of the white pulp of the spleen or the corticol areas of the peripheral lymph nodes. This cell type is also described as being CD19-positive, B220-positive, AA4-negative, CD43-negative, and CD5-negative. follicular B-lymphocyte Fo B-cell Follicular B cells are also reportedly CD48-positive, CD84-positive, CD229-positive, and CD352-positive. follicular B lymphocyte