A recent study (Liang et al., 2022) on 491 patients (65 years old or above) who received knee replacement, hip replacement or laminectomy found that preoperative plasma concentrations of phosphorylated tau at threonine 217 (p-Tau 217) and phosphorylated tau at threonine 181 (p-Tau 181) were related to postoperative delirium. Here, MAPT is linked to delirium.