This TNF-induced phenomenon was also observed in RA iTH+ cells, although untreated RA iTH+ cells did not show the same dendritic shape as OA cells, possibly because RA cells are already strongly primed by a higher TNF milieu within synovial tissue when compared to OA (RA: 0.1 and 5 ng/ml in RA, refs43,44, versus OA: 1–10 pg/ml, refs45,46). The gene discussed is TNF; the disease is rheumatoid arthritis.