Olfactory receptor family 4 subfamily F member 21 (OR4F21)

Olfactory receptor family 4 subfamily F member 21 (OR4F21) is listed as a human gene classified within the large family of olfactory receptors, which are G protein-coupled receptors (GPCRs) typically responsible for recognizing odorant molecules in the nose and mediate G protein signaling leading to the perception of smell[2][3][4]. However, in humans, **OR4F21 is annotated as a pseudogene**[2]. This means the gene likely does not encode a functional protein due to mutations or other genetic disruptions; thus, it is unlikely to have any normal biological function or direct disease role as a receptor. The olfactory receptor gene family is the largest in the human genome, with hundreds of pseudogenes that do not produce functional receptors[3][2]. No biological ligands, drugs, or clinical applications are known for OR4F21. There is no reported evidence that dysfunction or variation at this locus leads to any disease, nor is it a biomarker or therapeutic target. **Note**: Some database entries (such as the Ma'ayan Lab Harmonizome entry[2]) appear to conflate OR4F21 with unrelated RNA-binding proteins (e.g., hnRNP AB), but this is a likely error; authoritative sources classify OR4F21 as a pseudogene for an olfactory receptor, not an RNA-binding protein, and there is no peer-reviewed evidence to support a functional role outside canonical olfactory receptor GPCR biology. In summary: **OR4F21, also known as olfactory receptor 4F21, is a non-functional pseudogene in the human genome with no demonstrated physiological or pathological significance, and is not a clinical or drug target**[2][3][4].

Other names

Olfactory receptor 4F21OR4F21OR4F21Polfactory receptor, family 4, subfamily F, member 21 pseudogeneolfactory receptor 4F21