Small EDRK-rich factor 1 (SERF1A) is also named SMA modifier 1 (SMAM1). SERF1a is part of a 500 kb inverted duplication on chromosome 5q13 and highly related to spinal muscular atrophy. Human SERF1a protein has two isoforms. The short form contains 62 residues, and the long form has 110 amino acids. They share a highly conserved N-terminal region, and they are enriched in lysine and arginine (PMID: 37479809). SERF1a was found to promote amyloid formation in vitro on several amyloid proteins, including α-synuclein, huntingtin, Aβ, and prion proteins (PMID: 22854022). SERF1a has been reported as an RNA-binding protein capable of mediating the functional integration of RNA in the nucleolus (PMID: 31794729). This target may exhibit cross-reaction with SERF2.