CD274 and neoplasm: The affibody molecule PD-L1 (ZPD-L1_1) was conjugated to NOTA via its unique cystine and radiolabelled with the [18F]AlF complex ([18F]AlF-NOTA-ZPD-L1_1 in a radiochemical yield of 15.1 ± 5.6% and a molar activity of 14.6 ± 6.5 GBq/μmol; the radioconjugate differentiated between PD-L1 positive and negative tumours in vivo (González Trotter et al. 2017).