The relevance of our findings may not be limited to OA, as COMP has been shown to play a role in the progression of several types of cancer, pulmonary arterial hypertension, idiopathic pulmonary fibrosis, and skin fibrosis (reviewed in [86]), all diseases where circulating levels of the QQS77 neoepitope have not been measured in comparison to control subjects. This evidence concerns the gene COMP and pulmonary arterial hypertension.