Microenvironmental signals in additional to BCR that appear to be delivered in tissues important for the crosstalk between CLL cells and their microenvironments involve CD40 (138), TLR (152), B-cell activating factor receptor (BAFFr), and transmembrane activator CAML interactor (TACI) (153). This evidence concerns the gene TNFRSF13C and B-cell chronic lymphocytic leukemia.