TGM2 and mastocytosis: Furthermore, it was shown that in children with mastocytosis, MCs may migrate to the skin and BM as a result of the upregulation of CCL2/chemokine receptor 2 (CCR2) and vascular cell adhesion molecule (VCAM-1), and they may induce the expression/activation of transglutaminase 2 (TG2) [144].