PET ligands for the mitochondrial translocator protein (TSPO), such as 11C-PK11195, have been implemented as in vivo proxies of activated microglia, showing increased cerebral inflammation in patients across all of the FTLD syndromes.19-25 TSPO PET has shown that higher inflammation at baseline is strongly correlated with clinical severity and predicts faster clinical decline over the following years in FTD, PSP and Alzheimer’s disease.26-28. Here, TSPO is linked to frontotemporal dementia.