PPIF and Cognitive impairment: On the other hand, 17β-HSD10–cypD complexes in CSF, similarly as Aβ–τ complexes evaluated in our older study [42], do not reflect degree of cognitive impairment (we did not observe significant correlations with MMSE in ADD (R = − 0.035, p = 0.801) as well as in FTLD (R = + 0.098, p = 0.536) in this study).