Harnessing the high abundance of albumin in plasma, Käppeli et al. (2019) as well as Ikuni et al. (2022) introduced albumin binding moieties at different sites of the Ex4 sequence, which resulted in a reduced kidney uptake by up to 68% and increased tumour uptake at 4 h p.i. Introduction of cleavable linkers specific to meprin-β, a metalloproteinase highly abundant in the brush border membrane of the kidney, yielded promising in vitro results, but no in vivo reduction of kidney uptake was observed (Jodal et al. 2015). The gene discussed is ALB; the disease is neoplasm.