Chromatin from hMSCs and differentiated chondrocytes were extracted using the Diagenode iDeal histone ChIP-seq kit (Diagenode SA, Ougrée, Belgium). Extracted chromatin was sonicated using a Diagenode Bioruptor Standard or Bioruptor Pico to an average size of 200-500bp, using 15 sonication cycles (30s on/30s off). Replicate 1: Diagenode MicroPLEX v2 kit, replicate 2: NEBNext Ultra II kit (New England Biolabs, Hitchin, UK)