,6 NfL and phosphorylated NfH (pNfH) are significantly elevated in ALS,7, 8, 9, 10, 11, 12 with NfL extensively studied in AD,13, 14, 15 frontotemporal dementia (FTD),16, 17, 18 and Lewy body dementia (LBD),19,20 correlating with cognitive decline and neurodegeneration. The gene discussed is NEFH; the disease is Alzheimer disease.