The expression of transforming growth factor beta receptors (TGFβRI and TGFβRII) in both normal osteoblasts and five malignant canine OSA cell lines indicated that the TGFβ signaling pathway is not characteristic of the malignant phenotype but is active in reparative osteoblasts [53]. The gene discussed is TGFB1; the disease is obstructive sleep apnea syndrome.