NFKB1 and myeloid neoplasm: Likewise, while it is not yet clear what proportion of patients with any category of myeloid neoplasm feature NFκB signaling hyperactivation, our study using mass cytometry identified that, in CD34+ cells from the majority of MF patients studied, levels of phosphorylated, and hence active, NFκB subunit p65/Rela, were above the range observed in healthy controls (33).