Seven different osteosarcoma cell lines (MG-63, MHM, HOS-143B, IOR-OS18, HOS, ZK-58 and OSA) were assessed for basal secretion of ANGPTL4 which, with the exception of MG-63 and MHM cells, was almost undetectable. The gene discussed is ANGPTL4; the disease is obstructive sleep apnea syndrome.