After receiving informed consent, three blood samples of 5cc blood each will be drawn: the first - before tocilizumab treatment to set the basal level of expression in untreated patients, the second and third samples will be taken one month and four months after initiation of tocilizumab treatment. The investigators will use selected samples (from 5 patients) to perform microarray analysis for miRNAs expression, and based on the results, we will confirm the expression of specific miRNAs by quantitative real-time PCR (qPCR). Based on current knowledge, the investigators expect that miR-9, 16, 125, 132, 146a, 150, 155, 181 and, 223 will show significant changes in expression upon tocilizumab treatment. Cytokines levels are measured using ELISA tests for each individual biomarker. The changes in cytokines and miRNAs expression, either up-regulation or down-regulation, will be correlated to the severity of the disease and to the clinical effect of tocilizumab. Information regarding disease duration, activity as measured by disease activity score, concomitant treatment and serology status will be collected. Also demographic characteristics - age, sex and smoking status will be recorded. The results will be compared to 60 healthy controls gender- and age matched, without any rheumatic, inflammatory or malignant disorders