FURIN and Parkinson disease: We observed that two proteins, Tenascin‐R (TNR) and Furin (FURIN), showed a strong negative correlation with the MoCA score in PD patients (TNR Pearson r: −0.66; FURIN r: −0.65; P < 10−7 for both), mainly driven by LRRK2 G2019S carriers (TNR r: −0.77; FURIN r: −0.78; P < 10−5 for both) (Fig 5A and Appendix Fig S4).