MAPT and Alzheimer disease: We found that LLD patients showed significant higher Aβ42 CSF levels (837.33 ± 194.96 vs. 306.33 ± 105.69 pg/mL, p < 0.001) coupled with significant lower t-tau (205.41 ± 83.22 vs. 676.60 ± 373.53 pg/mL, p < 0.001) and p-tau (33.46 ± 9.56 vs. 86.67 ± 51.28 pg/mL, p < 0.001) CSF levels compared to AD patients.