The objective of the present study was to identify candidate factors involved in iron uptake, use and storage mechanisms in E. histolytica. We compared the transcriptome of E. histolytica trophozoites grown in vitro under four conditions: (i) normal iron concentrations (around 169 μM iron); (ii) low iron concentrations (around 123 μM); (iii) iron deficiency (91 μM) and (iv) iron deficiency with Hb replenishment. The gene discussed is GSTM1; the disease is nutritional disorder.