Fig 3A shows that ELMO1 siRNA, which decreased ELMO1 expression by >90%, significantly decreased cell migration in the wound closure assay. Control siRNA or siRNA specific for a related gene, namely ELMO2, had no effect. Cell invasion is another phenotypic feature of RA FLS and requires movement of cells into an extracellular matrix. Therefore, we determined if ELMO1 participates in FLS invasion into extracellular matrix. As shown in Fig 3B and 3C, ELMO1 deficiency markedly decreased FLS invasion into Matrigel, a commonly used matrix that is comprised mainly of laminin. This evidence concerns the gene ELMO2 and rheumatoid arthritis.