The Fos gene family consists of 4 members: FOS, FOSB, FOSL1, and FOSL2. These genes encode leucine zipper proteins that can dimerize with proteins of the JUN family, thereby forming the transcription factor complex AP-1. As such, the FOS proteins have been implicated as regulators of cell proliferation, differentiation, and transformation. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008] CIViC Summary for FOSB Gene
Forensic Context
A study in humans demonstrated that the FOSB mRNA is a differentially expressed gene exhibiting a consistent trend in expression from young adulthood to later life and was identified as a predictive feature for a robust age estimation model using peripheral blood, achieving a mean absolute error of 6.72 years on a test set [Liao et al. DOI:10.1016/J.Fsigen.2025.103373]. In a separate human study, the FOSB mRNA was found to be down-regulated in the stromal vascular fraction from erectile dysfunction patients compared to healthy controls, as validated by qRT-PCR, and was linked to altered TGF-β signaling pathways [Vishnubalaji et al. DOI:10.1042/BSR20181015]. A study in zebrafish demonstrated that the FOSB transcript, an AP-1 component, increased in abundance within 0.3 hours postmortem [Pozhitkov et al. DOI:10.1098/rsob.160267].