title: Author's response to the letter by Dr. Arjmand and Aghayan.
authors.affiliation: Department of Orthopedic Surgery, Seoul National University College of Medicine, SMG-SNU Boramae Medical Center, Dongjak-gu, Seoul, Korea.
authors.forename: Chris Hyunchul
authors.initials: CH
authors.lastname: Jo
authors.forename: Kang Sup
authors.initials: KS
authors.lastname: Yoon
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D005260:Female; D006801:Humans; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D020370:Osteoarthritis, Knee / Q000628:therapy*
keywords: Adipose-tissue derived mesenchymal stem cells; Cartilage regeneration; Intra-articular injection; Osteoarthritis