We investigated transcriptional response of CaCo-2 cells to iron treatments, we studied hemin effect by adding hemin to DMEM-FBS medium and iron deficiency effects in using an iron free medium compared to the same supplemented with FAC (ferric ammonium citrate). Experiment Overall Design: Biological replicates were used (3 samples) of each iron treatments (SF-FAC, SF-0, DMEM-FBS, DMEM-Hemin). Each sample was labelled with cy5 and a pool of each sample was constituted and labelled with cy3.