While previously antibody-mediated PD-1 immune checkpoint blockade, which is currently used as immunotherapy to treat cancer (Pardoll et al., 2012), has been suggested as a novel therapeutic strategy to tackle AD and potentially other neurodegenerative diseases (Baruch et al., 2016), a very recent publication showed that PD-1 blockade has no effect on Aβ pathology in 3 different models of AD (Latta-Mahieu et al., 2017). Here, PDCD1 is linked to Alzheimer disease.