Possible mechanisms of contribution of LOX to progression of myelofibrosis. Low-ploidy MKs have elevated levels of expression of LOX, which is secreted to the BM microenvironment. The active LOX enzyme promotes cross-linking of matrix collagen and consequent fiber deposition. The active LOX enzyme also oxidizes the PDGF receptor, enhancing the proliferative response from this receptor. Inhibition of LOX by BAPN may reverse this process. High-ploidy MKs express very low amounts of LOX.