PTK7 and breast cancer: Then, while PTK7-GEMs (fluorescein isothiocyanate, FITC) and its control sequence, LIB-GEMs (FITC), was incubated with the PTK7-high expression 5637 cell line and the PTK7 negative expression SV-HUC-1 cell line respectively, we can observe that PTK7-GEMs (orange) showed a higher fluorescence intensity than LIBGEMs (blue) on 5637 cells (Fig. 2C), indicated that PTK7-GEMs can specifically bind to 5637 cells than LIB-GEMs, which verify the targeting of PTK7-GEMs through cell membrane surface PTK7 to BC cells.