The results showed that canine OSA cell lines express mRNA and protein for TrkA, that blocking TrkA signaling with a protein kinase inhibitor or an NGF-neutralizing mAb induced apoptosis in the same cell lines, and that the majority of spontaneously occurring primary tumors and lung metastases of canine OSA express TrkA protein. This evidence concerns the gene NGF and obstructive sleep apnea syndrome.