Similar to that observed in CCSP-rtTA/(TetO)7-CMV-Stat3C bitransgenic mice, the increased CHI3L1 protein concentration was observed in BALF and serum of doxycycline-treated CCSP-rtTA/(TetO)7-CMV-MMP12 and CCSP-rtTA/(TetO)7-CMV-Api6 bitransgenic mice with tumor. This evidence concerns the gene CHI3L1 and neoplasm.