HDGFL2 and amyotrophic lateral sclerosis: The first study described the development of a monoclonal antibody that detects a TDP-43-dependent epitope in the hepatoma-derived growth factor-related protein 2, encoded by the inclusion of a cryptic exon.95 Importantly, cryptic HDGF-related protein 2 can be detected using standard clinical laboratory techniques, such as enzyme-linked immunosorbent assay, in the blood of people with ALS or frontotemporal dementia, as well as in presymptomatic carriers of C9orf72 mutations, highlighting the potential value of this biomarker in early detection and treatment trials in the future.