However, we show that: 1) BALF EGF levels are very low and do not differ between naïve and tumor-bearing lungs; 2) macrophages produce trace amounts of EGF in vitro; and 3) EGF does not stimulate neoplastic lung proliferation either alone or in combination with IGF-1 or MØCM (Figures 6, 7 and data not shown). The gene discussed is EGF; the disease is neoplasm.