We revealed that tau-SA was significantly decreased in the samples subjected to ID compared to the samples without ID [41,285 ± 20,657 (AD_ID skin, mean ± SD) vs. 149,573 ± 61,571 (AD skin), p < 0.0001] (Fig. S5), confirming the specificity of tau-SA by RT-QuIC. The gene discussed is MAPT; the disease is Alzheimer disease.