IL-22 production was considered characteristic of the CD3+ CD4+ CCR4+ CCR6+ CCR10+ cells, and as their ability to produce this cytokine exceeded that of other subgroups of Th Cells, the population was designated as Th22. It has been reported that co-culture of Th22 cells with monocytes in the presence of M-CSF and RANKL induced osteoclast formation more efficiently than Th1 cells or Th17 cells from RA patients (55). This evidence concerns the gene CSF1 and rheumatoid arthritis.