Figure 1 .

Increased STAT1 phosphorylation on tyrosine and serine in RA ST as compared with controls. Serial ST sections from 12 patients with RA and 14 controls were stained for STAT1-phospho-tyrosine and STAT1-phospho-serine using aminoethylcarbazole as dye (A) representative sections are shown. Counterstaining was performed using Mayer's haematoxylin. (Original magnification x400.) Sections were analysed using computer assisted digital image analysis (B). Results are shown as means, errors bars indicate SD; on the y axis the mean IOD per mm² of tissue (see "Materials and methods") is shown.