IL10 and Arthritis: Gene microarray analyses of infected joint tissues from B6-IL-10-/- mice determined that the gene expression patterns were more similar to those for infected C3H mice displaying severe disease, as opposed to infected B6 mice that develop mild disease [39], and blocking these IL-10 mediated responses reduced the infiltration of different immune cells whose presence is associated with increased arthritis severity [40], suggesting an important role for IL-10 in mediating Lyme-associated pathology.