TXN and infection: The participation of this domain on phagocytosis during infection resistance and feeding observed in the evolutionary related ameba Dictyostelium discoideum[13,15,30], led us to think that the thioredoxin found, may participate in the phagocytosis of natural sources of nutrients through human commensal bacteria (such as Escherichia coli) and erythrocytes to uptake iron[23].