Model of the phenotype of CLL cells exiting the lymph node into the blood or exiting the blood into the LN. Within the PCs of the lymph node, CLL cells are stimulated via factors in the microenvironment (eg, CD154 or BAFF/APRIL), where there is upregulation of miR-155 and downregulation of INPP5D. The CLL cells that recently have exited the LN express relatively low levels of CXCR4 (CXCR4^Dim), high levels of CD5 (CD5^Bright), high levels of miR-155 (miR-155^High), and low levels of SHIP1 (SHIP1^Low), and have high responsiveness to BCR ligation with anti-µ (BCR-signaling^High). Conversely, the cells that may exit the blood for the LN are CXCR4^BrightCD5^Dim and have relatively low levels of miR-155 (miR-155^Low), high levels of SHIP1 (SHIP1^High), and relatively low responsiveness to BCR ligation with anti-µ (BCR-signaling^Low). The arrows indicate the direction of trafficking from the blood to the lymph node and then back to the blood.