The other two MPN driver gene mutations, MPL and CALR, have also been captured in MPN patient-derived iPSCs and shown to model thrombopoietin-independent megakaryocytic colony formation (Liu et al., 2017a; Takei et al., 2018; Gomez Limia et al., 2017). The gene discussed is CALR; the disease is myeloproliferative neoplasm.