The classical feature of BM myelofibrosis consist in the deposition of reticulin and collagen fibers by marrow stroma (151) and the iPSC-based organoid model was able to recapitulate them when the donor cells derived from patients with myelofibrosis but not when derived from healty donor: increased soluble TGFβ levels, collagen 1 and α-SMA and reduced vascularization was observed (126). This evidence concerns the gene ACTA1 and myelofibrosis.