A plethora of humoral factors such as the vitamin D hormone (Fig. 1), phosphate, calcium, parathyroid hormone (PTH),aldosterone, iron deficiency, and pro-inflammatory cytokines has been shown to directly orindirectly stimulate osteoblastic/osteocytic FGF23 secretion (Martin, David, and Quarles 2012; Quinn et al. 2013; Wolf and White 2014; Ito et al. 2015; David et al. 2016; Pathak et al. 2016; B. Zhang et al. 2016). The gene discussed is PTH; the disease is Iron deficiency anemia.