The same study group analyzed the effect, in vivo, of the PMBL (orally administrated)in preventing recurrent infections of the upper respiratory tract (URTIs) in a groupof patients with a medical history of URTI recurrence.17 Clinical resultswere correlated to the levels of IgM memory B cells and the expression of theactivation marker CD25 in peripheral blood lymphocytes using the flow cytometricmethod, before and at 1 and 3 months after the treatment. The gene discussed is CD40LG; the disease is infection.