A role of oxidative stress in GO is supported by a number of basic studies suggesting that ROS promote the proliferation of OFs and the release of GAGs, the synthesis and secretion of cytokines, and the expression of other factors involved in the pathogenesis of GO, namely heat shock protein 72 (HSP-72), HLA-DR and ICAM-1 (14). This evidence concerns the gene ICAM1 and geroderma osteodysplastica.