To overcome the poor selectivity of PS, oestrogen receptors, epithelial growth receptors and HER-2 antigens expressed by breast cancer cells have been targeted by ligands or antibody/antibody fragments for the development of tPDT (Gijsens et al, 2000; Swamy et al, 2002, 2006; Savellano et al, 2005; Bhatti et al, 2008). Here, ERBB2 is linked to breast cancer.