NFE2L2 and Iron deficiency anemia: The expression of TfR, including TfR1 and TfR2 [26], is determined by cellular iron levels, health, hormones, and inflammation, and is boosted by conditions such as iron deficiency [27], hypoxia-inducible factor (HIF) [28], signal transducer and activator of transcription 5 (STAT5, a transcription factor activated by erythropoietin) [29], Ets-1 [30], nuclear factor erythroid 2-related factor 2 (Nrf2) [31], and GATA-1 [32].