Human fibroblasts are derived from cultured skin explants. Human fibroblasts are from a single donor. These cells enable researchers to study skin diseases such as dermatitis, wound healing, and other diseases that are expressed in fibroblast. In addition, they may be used to study the development of skin and production of inducible pluripotent stem cells to study disease models. Fibroblasts are isolated from an individual who has been clinically diagnosed with rheumatoid arthritis. RA is a is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks the joints producing an inflammatory synovitis that often progresses to destruction of the articular cartilage and ankylosis of the joints.