ERBB2 and cancer: Subsequent assays utilizing phycoerythrin (PE)‐labeled TZ and TZ‐dSA3‐12 exhibited significant fluorescence in HER2‐positive SKOV3 cells, while displaying weak fluorescence in HER2‐negative MCF‐7 cells, indicating that TZ‐dSA3‐12 specifically targets the HER2 antigen present on cancer cells (Figure 3g).