Conversely, even in the second experiment, in which the inoculum dose was increased from 5,000 to 10,000 pfu, the viral load in rRB-1B_Meq77/80-infected chickens did not increase, possibly because of the reduced transformation ability of Meq77/80 and lower proliferation of lymphoma cells, consistent with the observation that Meq+ CD4+ T cells did not increase in most rRB-1B_Meq77/80-infected chickens. The gene discussed is CD4; the disease is lymphoma.