In this review we could however identify the following pathologies in which challengers were efficient in strengthening initials results suggested by (R)-[11C]PK11195 studies and/or in renewing an interest in TSPO imaging: Alzheimer’s and Parkinson’s disease, amyotrophic lateral sclerosis, multiple sclerosis, epilepsy, rheumatoid arthritis. The gene discussed is TSPO; the disease is rheumatoid arthritis.