In this study, it was determined that CLL with a high level of miR-155 expressed lower levels of Src homology-2 domain-containing inositol 5-phosphatase 1 (SHIP1), a phosphatase that may suppress surface immunoglobulin, enhancing the sensitivity to BCR ligation compared to CLL with low levels of miR-155. The gene discussed is BCR; the disease is B-cell chronic lymphocytic leukemia.