Two different groups of osteoblasts have been found in osteoarthritis, called low osteoarthritis osteoblasts, which are analogous to normal osteoblasts and are characterized by low levels of prostaglandin E2 (PGE2) and interleukin‐6 (IL‐6), and high osteoarthritis osteoblasts, which are characterized by high levels of PGE2 and IL‐6 (Massicotte et al., 2002). Here, IL6 is linked to osteoarthritis.