SSBP3 (single-stranded DNA-binding protein 3) is a transcriptional coregulator that functions as an essential component of the LIM-homeodomain transcription factor complex. While originally characterized for DNA binding capabilities, SSBP3's primary role is stabilizing transcriptional complexes through direct interaction with architectural cofactor LDB1 and transcription factors like Isl1 1. SSBP3 stabilizes LDB1 dimerization and is critical for LDB1-mediated chr1 looping and gene transcription, with only SSBP3 being essential among SSBP family members for erythroid cell viability 1. In pancreatic β-cells, SSBP3 interacts with Isl1 and Ldb1 to regulate target genes MafA and Glp1r, with SSBP3 deletion causing hyperglycemia, glucose intolerance, and reduced glucose-stimulated insulin secretion 2. SSBP3 is dosage-sensitive, with altered expression levels affecting neurodevelopment; its overexpression in Drosophila caused anatomical abnormalities, altered synaptic density, oxidative stress pathway perturbation, and autism-associated behavioral defects 3. SSBP3 stability is regulated by the E3 ubiquitin ligase SIVA1, which controls its proteasomal degradation 4. Genetic variants in SSBP3 associate with skin hydration through epidermal differentiation regulation 5 and with migraine and Fuchs corneal dystrophy susceptibility 6, 7.