In this regard, SMZL usually presents with lymphocyte counts ≥4 × 109/L, atypical lymphocytes are easily recognized in the morphological study of PB, the median percentage of B lymphocytes from the total lymphocyte count is usually >20%, and the percentage of clonal CD19/total CD19 in PB is almost always higher than in WM. This evidence concerns the gene CD19 and splenic marginal zone lymphoma.