In PD population, higher CSF NfL baseline concentration predicted faster decline in global cognition (MOCA, β = −0.010, p = 0.011), episodic memory (HVLT Total Recall, β = −0.016, p = 0.006; HVLT Delayed Recall, β = −0.030, p < 0.001; HVLT Retention, β = −0.034, p < 0.001), verbal working memory (LNS, β = −0.026, p = 0.008), language (Semantic Fluency Test, β = −0.022, p < 0.001) and processing speed-attention (SDMT, β = −0.025, p < 0.001; Figure 2A). This evidence concerns the gene NEFL and Parkinson disease.