CXCR4 and myelofibrosis: Importantly, upregulation of CXCL12, ASPN, and OLFM3, factors secreted by CAF, has been observed; CXCL12, through the interaction with its receptor CXCR4, can lead to CXCL12 and TGFβ production and concur to myelofibrosis (205).