ACAN and cyclic hematopoiesis: We measured decreased gene expression of SOX9, ACAN (Figures 4A, B) and ITGA11 (Figure 4E) in OA-CH after addition of 10-8 and 10-10M SP, and of COL9A1 and COL2A1 in the presence of 10-10M SP (Figures 4F, G).