 The FOXO (Forkhead Box O) gene sub-family encodes tumour-suppressive transcription factors that regulate multiple aspects of cell cycle progression and survival.FOXO1 protein expression is down-regulated in breast tumour tissue samples; miR-27a has been identified as one of three miRNAS (along with miR-96 and miR-182) which directly target FOXO1 and regulate its endogenous expression.Suppression of miR-27a results in a FOXO1 protein increase and a consequent cell number decrease.