IL1B and synovitis: Another example emphasizing the significance of tissue cross‐talk is represented by the mesenchymal stem‐cell derived miniJoint, in which a synovitis model was first recapitulated by exposing the synovial fibrous tissue to IL1β, followed by assessment of its impact on osteochondral and adipose tissues.[35] Interestingly, the osteochondral complex showed signs of OA induction, such as downregulation of collagen type‐II and aggrecan, and upregulation of IL8 and MMP13.