The fact that this analogy arose from studies in myeloid cells is reminiscent of the original observation of Ito and colleagues(121) that human myelogenous leukemia K562 cells were one of the few cell types that expressed significant levels of FGF23 mRNA, most likely because of the rich background of MZF1 that occurs in myeloid leukemia cells. The gene discussed is FGF23; the disease is myeloid leukemia.