SEMA4D and Huntington disease: Among antibody-based therapies and immune modulators—seven antibodies are currently in phase III trials that are targeted to reduce immune factors, including CGRP for migraine; semaphorin 4D (Huntington’s disease); nerve growth factor; tau, α-synuclein, and amyloid β (Alzheimer’s disease, ALS, Parkinson’s disease), demonstrating current thinking and the diversity of available targets for immunotherapy in neurological disorders [36,37].