To test this hypothesis and investigate the role of PARP1 in neuroinflammation and neurodegenerative diseases, Reilly et al. (Mach lab) developed an 18F labelled analogue of AZD2461 in 2019, called [18F]9e. However, [18F]9e showed non-appreciable brain-uptake in non-human primates, suggesting that [18F]9e does not cross the BBB and is hence not suitable to investigate PARP1 in neurodegenerative diseases [55]. Here, PARP1 is linked to neurodegenerative disease.