Interestingly, Syk (see below) has been shown to regulate the expression of differentially expressed MMPs such as Mmp3[17] and Mmp9[18], further suggesting a potential central role for Syk in arthritis and a Syk-regulatory effect of Cia5a. Components of the extracellular matrix (ECM; Cthrc1, Col12a1, Emilin1) also had reduced expression in congenics, and together with the levels of proteases suggested that there was reduced matrix turnover and reduced degradation, compared with arthritic DA rats (Table 3). This evidence concerns the gene SYK and arthritic joint disease.