So far, structural optimization efforts have yielded the AQ descendant 1 exhibiting improved Nurr1 agonist potency and protective effects in a PD model36, simplified 7-chloroquinolin-4-amine (2) and 8-chloro-2-methylquinolin-4-amine (3) fragments with enhanced Nurr1 agonism28, and a 5-(4-chlorophenyl)furan-2-carboxamide motif (4)37 as replacement for the unfavorable 4-aminophenol residue of AQ. Here, NR4A2 is linked to Parkinson disease.