Among these tracers, PBB3 is reported to bind tovarious types of tau fibrils with comparable binding affinities.In contrast, tau tracer AV-1451 is reported to bind to specific typesof tau fibrils (in particular to AD-associated and CTE) with higherbinding affinity and only show nonspecific or weaker binding towardtau fibrils dominant with 3R isoforms (associated with PiD). This evidence concerns the gene MAPT and pelvic inflammatory disease.