HSP90AA1 and neoplasm: In agreement with autoradiography results to U87 tumour tissue slices, both homologous (SNX-ab, SNX-0723) and heterologous (Onalespib) inhibitors showed no efficient blocking of intra- and extracellular tracer binding, although these blocking agents were able to reduce tracer binding up to 95% in U87 cell binding experiments using our previously developed Hsp90 PET probes (Cools et al. 2022).