In this context, the increased number of classical monocytes and the enhanced expression of CD115 may predispose patients to developing bone loss, since classical monocytes have been associated with cells that transform into osteoclasts in rheumatoid arthritis by several authors [59,60,61], and the activation of CD115 by MCSF promotes a greater expression of RANK and, therefore, induces an intensified osteoclastogenic capacity. This evidence concerns the gene CSF1R and rheumatoid arthritis.