The key findings were; 1) The cellular infiltrate in NSIP is largely composed of lymphocytes with a relatively high CD4/CD8 ratio, 2) A large proportion of the mononuclear cells express the B cell specific antigen CD20, and 3) Cytokine expression was substantially greater in NSIP compared with UIP tissues. The gene discussed is CD4; the disease is idiopathic pulmonary fibrosis.