IL17A and disease of the tendon: The observed phenotype of tendon degeneration is proposed to be linked with IL-17A-induced downstream upregulation of matrix metalloproteinase expression, which may disrupt extracellular matrix homeostasis due to augmented matrix protein degradation.18 30 Our mechanistic data generated in tendon fascicles suggest that blockade of IL-17A signal induction controls the downstream inflammatory IL-17A signalling cascade and may prevent progression of tendon degeneration in tendinopathy.