In the c-fms-rtTA/(TetO)7-CMV-MMP12 spontaneous lung tumor mouse model, the average CHI3L1 concentration in BALF of doxycycline-treated mice with tumor (70.9±36.5 ng/ml) was 4-fold increase in comparison with that in BALF of doxycycline-untreated mice (17.7±13.8 ng/ml, p = 0.027, Figure 4A, upper left panel). The gene discussed is MMP12; the disease is neoplasm.