OSM induces IL-6 synthesis from RA-FLS. RA-FLSwere stimulated with recombinant OSM (20 ng/day) in the presence or absence of CP690,550 (500 nM) for 24 hours. The levels of cytokines and chemokines in RA-FLS-conditioned media were subjected to cytokine antibody array as described in Material and methods. The indicated dots of cytokines or chemokines were calculated as a relative unit by densitometer. The dots of each protein of untreated condition (upper column) were assigned the value of 1.0 and the density of each dots of OSM or OSM plus CP690,550 treated condition (middle or lower column) was expressed as the relative unit. Two experiments were performed using different RA-FLS and a representative result is shown.