Tau is a microtubule-associated protein encoded by the MAPT gene, critical for microtubule stabilization and axonal transport in neurons. In neurodegenerative diseases such as Alzheimer’s disease, frontotemporal dementia, and progressive supranuclear palsy, hyperphosphorylated tau aggregates into neurofibrillary tangles, disrupting cytoskeletal integrity and impairing neuronal function. Phosphorylated tau isoforms (p-tau181, p-tau217, p-tau231) in cerebrospinal fluid and plasma are established biomarkers for Alzheimer’s diagnosis, disease progression, and therapeutic monitoring. Tau-targeted PET tracers and antibody-based therapies are further enhancing early detection and intervention in tauopathies. Catalina’s tau antibodies demonstrate high specificity and sensitivity, providing reliable tools for advanced Alzheimer’s and neurodegeneration research.