It has previously been demonstrated that in tendon biopsies of human tendinopathy, IL-17A mRNA (IL17A) and IL-17A protein are upregulated.10 18 Here, we describe that only IL-17A, and no other IL-17 family member is differentially expressed in rotator cuff tendon biopsies of human early-stage tendinopathy. This evidence concerns the gene IL17A and disease of the tendon.