According to the results in the tendinopathy model established by Millar et al., the imbalance in matrix homeostasis induced in the early stages of tendon injury is caused by interleukin-33 (IL-33) secreted by tendon cells, which activates ST2 receptors and thus increases type III collagen synthesis, the most typical manifestation of the inflammatory phase (Liu et al. 2021b; Millar et al. 2015; Xiao et al. 2019). Here, IL33 is linked to disease of the tendon.