OSTF1 (Osteoclast Stimulating Factor 1) is a Protein Coding gene. The OSTF1 gene, located on 9q21.13, is conserved in chimpanzee, Rhesus monkey, dog, cow, mouse, rat, chicken, zebrafish, C.elegans, and frog. Ostf1 was first discovered by subtractive hybridization in the gills of Mozambique tilapia (Oreochromis mossambicus) transferred from Freshwater (FW) to seawater (SW). OSTF1 is an SH3 domain-containing protein that was initially identified as a factor involved in the indirect activation of osteoclasts. It has been linked to spinal muscular atrophy in humans through its interaction with SMN1 and is one of six genes deleted in a human developmental microdeletion syndrome. Diseases associated with OSTF1 include Narcissistic Personality Disorder and Stork Bite. Among its related pathways is the Innate Immune System.