HAMP and Iron deficiency anemia: We hypothesize that relative hepcidin suppression without recovery from iron deficiency in PV may result from the combined effects of concurrent inflammation, insufficiently elevated ERFE with insufficiently suppressed hepcidin, and/or aberrant hypoxia signaling in the intestine preventing recovery from iron deficiency (Nemeth and Ganz, 2014; Frise et al., 2016; Shah et al., 2009).