PFN1 and amyotrophic lateral sclerosis: In the past twenty years, other ALS genes have been discovered, including TAR DNA-binding protein (TARDBP), Fused in Sarcoma (FUS), Angiogenin (ANG), Valosin-containing protein (VCP), Sequestosome 1 (SQSTM1), and Profilin 1 (PFN1).