Hemarthrosis inducesmdm2expression in mouse synovium. Synovial tissue was isolated from the right and left knee joints of 10 hemophilic mice and the RNA isolated then pooled and probed using a gene expression microarray assay. The expression of mdm2 and GAPDH are shown in tissue from the injured (right) and uninjured (left) control joints. This experiment was repeated with similar changes in mdm2 gene expression.