Identification and verification of KIAA1199 expression in rheumatoid arthritis (RA) patients and normal subjects. (A) Identification the over-expression of KIAA1199 in RA fibroblast-like synoviocyte (FLS) cells than in normal FLS cells from synovial membrane by automated 2D-Nano-LC-ESI-MS/MS. The left panel shows amino acid coverage of the identified KIAA1199 sequence; yellow, appraisal sequence of amino acids. The right panel is the normalized spectrum count in RA and normal subjects; *P <0.001. (B) Verification of the expression of KIAA1199 was performed in synovial tissues from 19 patients with inactive RA, 25 with active RA and 15 normal subjects by qPCR. Results were normalized for the amount of β-actin as internal control. Experiments were performed at least in triplicates; bars represents mean ± SD; *P <0.05 compared with normal. (C) Immunohistochemical staining of KIAA1199 was performed on synovial tissues from patients with inactive or active RA and normal subjects. The KIAA1199 protein was over-expressed in vascular endothelium in active and inactive RA synovial membrane compared to normal synovial membrane. (D) Immunofluorescence microscopy of KIAA1199 and CTGF was performed in FLS cells from RA patients. Result shows KIAA1199 and CTGF were co-expressed in FLS cells, were either not expressed or only very weakly expressed in the nucleus, and were strongly expressed in the cytoplasm and membrane of FLS cells.