Similarly, there was a significant over-usage of IGHD3-10 (p= 0.002), IGHD6-13 (p= 0.0001) and IGHD2-21 (p= 0.03) genes and under-usage of IGHD3-3 (p= 0.0001) and IGHD2-2 (p= 0.02) genes in Chinese CLL. This evidence concerns the gene BTK and B-cell chronic lymphocytic leukemia.