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. [ http://en.wikipedia.org/wiki/Follicular_B_Cells https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2193793 http://www.ncbi.nlm.nih.gov/pubmed/20933013 https://www.worldcat.org/search?q=bn%3A0781735149 ]