Moreover, HP1α encoding mRNA and protein have also been shown to be down-regulated in highly invasive breast cancer cell lines (e.g. HS578T and MDA-MB-231) compared to poorly invasive breast cancer cell lines (e.g. T47D and MCF7) while HP1β and HP1γ were relative equally expressed [20, 35–37]. The gene discussed is TFF3; the disease is breast carcinoma.