Among P-tau subtypes, p-tau-181 (Mielke et al., 2018; Tatebe et al., 2017; Thijssen et al., 2020; Karikari et al., 2020), p-tau-217 (Barthélemy et al., 2020; Palmqvist et al., 2020; Janelidze et al., 2020), and p-tau-231 (Hampel et al., 2005) have been useful for the detection of cognitive impairment, AD, and dementia. The gene discussed is MAPT; the disease is Alzheimer disease.