32 patients (40 Achilles tendons), suffering from persistent Achilles tendinosis, were randomized to assess the safety and efficacy of autologous skin-derived fibroblast injection. Patients either received an injection with autologous fibroblasts or with an anesthetic. Patients receiving an anesthetic injection also received physiotherapy. Blinded outcome assessment indicated that VISA and VAS pain scores were significantly reduced in the autologous fibroblast group, but not in the control group at 6 month follow-up. The Journal of Bone and Joint Surgery released a letter expressing concern of potential unethical behavior with regard to the research published in this article. Readers should be aware of these concerns and interpret this research with extreme caution.