Preclinical animal studies showed that the TNFα inhibitor infliximab had a positive effect on the restoration of callus formation and biomechanical properties of fractured bone in wild-type rats under chronic inflammatory conditions.27 In contrast, a human cohort study in ankylosing spondylitis patients demonstrated the negative long-term effect of TNFα inhibitor treatment on fracture healing.28 Therefore, there is an urgent need to develop molecular therapies for fracture nonunion, especially for older patients with chronic inflammatory diseases. Here, TNF is linked to ankylosing spondylitis.