ANXA5 and obstructive sleep apnea syndrome: Although TUNEL staining and caspase-3/-7 activity assay suggest a trend towards apoptosis, additionally we evaluated the apoptosis profiles in canine OSA cells at 48 hours post-treatment (5 nM) employing a bivariate Propidium Iodide (PI)/Annexin-V analysis, which was performed by flow cytometry (Fig 3).