Transcription factor that binds to DNA at the 5'-AACAATG-3' consensus sequence (By similarity). Acts as a transcriptional activator and repressor (By similarity). Binds synergistically with POU5F1 (OCT3/4) to gene promoters (By similarity). Binds to the FOXK1 promoter and recruits FHL3, resulting in transcriptional activation of FOXK1 which leads to myoblast proliferation (By similarity). Acts as an inhibitor of myoblast differentiation via transcriptional repression which leads to down-regulation of the muscle-specific genes MYOD and MYOG (By similarity). Involved in trophoblast giant cell differentiation via enhancement of HAND1 transcriptional activity (By similarity). Regulates transcription of HRC via binding to it proximal enhancer region (By similarity). Involved in skeletal muscle regeneration (By similarity). Also plays a role in the development of myogenic precursor cells (By similarity). . This is the function of SOX15 (SRY-box transcription factor 15, ENSG00000129194).