We measured plasma cell differentiation, proliferation, cell death, and B-cell activation, the latter using the markers CD80, CD86, and CD25.<h4>Results</h4>We did not detect significant differences supporting the hypothesis that CLL-derived soluble factors negatively influence the proliferation, activation, or cell death levels of normal B cells from healthy individuals in <i>in vitro</i> coculture.<h4>Discussion</h4>Our analysis suggests no major direct inhibitory effects of CLL-derived soluble factors on normal mature B cells. The gene discussed is CD80; the disease is B-cell chronic lymphocytic leukemia.