Gating strategy and naive/memory B-cell profile in MFC. (A) Lymphocytes were gated as CD45+/SS low cells. (B) Then, CLL cells were gated as CD19+/CD5+ lymphocytes. Normal residual B cells are CD19+/CD5− lymphocytes. (C) Naive (IgD+/CD27−) and memory (IgD−/CD27+) status of B-cell lymphocytes was finally determined.