Table 1 shows that an average of 75% of the RA and OA SF cells at the first passage were fibroblasts (Prolyl-4-hydroxylase +; mAb 5B5, Dianova, Hamburg, Germany) and 15% were macrophages (CD14+; mAb Tyk4, Dako, Hamburg, Germany), while T cells (CD-3+; mAb UCHT-1, ATCC, Manassas, VA, USA) and B cells (CD 20+; mAb B-Ly1, Dako, Hamburg, Germany) represent less than 1% of the SF cells. Here, CD14 is linked to rheumatoid arthritis.