For example, Sgc8c, also used in the programmable DNA origami robot mentioned above [70], targets protein tyrosine kinase 7 (PTK7), a transmembrane receptor that is highly expressed in cancer cell lines including T-cell acute lymphoblastic leukemia [76], while the MUC-1 aptamer, S2.2, which is also used in DNA nanosphere work [88], targets MUC-1 receptor positive cancer cell lines including MCF-7 breast cancer cells [89]. Here, PTK7 is linked to breast carcinoma.