PMA stimulation of PBMC revealed a statistically significant difference between the frequencies of both B and T cells expressing the CD69 activation marker in both groups studied; the CD69+ B cell compartment was higher than the CD69+ T cell subset (CLL: p = 0.0385 and HC: p = 0.0113; data not shown). The gene discussed is CD69; the disease is B-cell chronic lymphocytic leukemia.