To further explore the seeding selectivity of the K12CFh substrate, we performed serial dilution analyses on several brain homogenates with confirmed 3R pathology (PiD), mixed 3R/4R pathology (sAD, fAD, CTE, PART), and controls that had either 4R pathology (PSP, CBD, AGD) or lacked tau pathology according to immunohistochemical analysis. This evidence concerns the gene MAPT and argyrophilic grain disease.