FOLH1 and neoplasm: Furthermore, other novel radiotracers are being developed and applied for the in vivo measurement of different aspects of breast cancer, such as cell proliferation and tumor metastasis (18F-fluorothymidine), tissue hypoxia (18F-Fluoromisonidazole), receptor status, tumor antigen levels (68Ga-PSMA), and therapeutic response (18F-Fluciclovine) [57].