FAP and neoplasm: Consistent with the biodistribution data, tumor uptake of the heterodimeric tracers [18F]AlF-PSMA-FAPI-01 and [18F]AlF-PSMA-FAPI-02 was higher than that of the monomeric tracers [18F]FAPI-42 and [18F]AlF-PSMA-BCH in both 22Rv1 and A549-FAP tumors 20 min p.i. When co-injected with the respective competitors, the tumor uptake of both [18F]AlF-PSMA-FAPI-01 and [18F]AlF-PSMA-FAPI-02 in A549-FAP and 22Rv1 tumors significantly decreased, implying dual targeting FAP/PSMA specificity in vivo.