By tracking the distinct fluorescence signals of VPF, we examined the cellular uptake of NanoTAC in the murine mammary carcinoma cell line 4T1, which mimics stage IV TNBC and overexpresses Cat-B.54–56 Its cellular accumulation increased gradually in a time-dependent manner, plateauing after 12 h of treatment, similar to VPF (Fig. 2a and Supplementary Fig. 14). Here, TYRP1 is linked to breast carcinoma.