PTK7 and neoplasm: For example, Zhang et al. demonstrated that Sgc8 aptamer-modified DNA nanoflowers (NFs) can selectively recognize the cell membrane protein tyrosine kinase 7, and Sgc8-NFs-Ferrocene/Doxorubicin can be selectively protein tyrosine kinase 7 positive cancer cells, significantly improving the tumor-targeting ability of the drug (Zhang Q. et al., 2019).