TTR and amyloidosis: Among the many posible analogues a difluorophenyl derivative, namely, diflunisal (2′,4′-difluoro-4-hydroxy-[1,1′-biphenyl]-3-carboxylic acid) was selected since it is an already registered drug [47] having a biphenyl core structure which complies with the two-ring model of TTR inhibitors shows a good TTR amyloid inhibitory profile [48]–[52], and is under clinical trials for TTR-related amyloidosis [53].