Using a similar culture systems, in this study we sought to investigate the impact of B-cell differentiation on the expression of factors that contribute to the physiopathology of CLL and/or are known to be deregulated in CLL B-cells (including LEF1, TCL1, ROR1, FMOD, TACI, PI3K, BTK and p27). The gene discussed is TCL1A; the disease is B-cell chronic lymphocytic leukemia.