Second, we examined the mechanistic basis of the differences in breast tumour cell responses to TSA, depending on tumour aggressiveness, and considered the transcriptional regulation of CXCR4 and Met, two genes important for tumour cell invasiveness (Benvenuti and Comoglio, 2007; Furlan et al, 2008). The gene discussed is CXCR4; the disease is neoplasm.