Osteoarthritis (OA) is the most common form of joint disease. This presents the OA research community and pharmaceutical companies developing disease-modifying OA drugs (DMOADs) with great opportunities. The different OA subtypes complicate the traditional approaches for developing new treatments. If we can identify new markers that can distinguish different subtypes this could greatly facilitate drug development from early discovery to late clinical development. Nevertheless, the current approaches result in poorly targeted treatments and the inability to recruit the right patients for clinical trials. Thus, there is an urgent medical need for objective biomarker tools for patient phenotyping.