Keratin 18 pseudogene 40 (KRT18P40)

Keratin 18 pseudogene 40 (KRT18P40) is a processed pseudogene related to the *keratin 18* (KRT18) gene, belonging to the large keratin gene family, which encodes the type I intermediate filament protein Keratin 18. Pseudogenes such as KRT18P40 are non-coding, non-functional genetic elements that originate from retrotransposition or gene duplication events, and they do not produce functional proteins[3][4][5]. The human genome contains a high number of processed pseudogenes for keratin 8 and keratin 18, dispersed throughout various chromosomes; specifically, there are at least 77 processed pseudogenes for keratin 18[3][5]. None of these processed pseudogenes contain an intact reading frame or are expressed as functional proteins[4][5]. Therefore, KRT18P40 is not a therapeutic target, does not have biological function, disease role, drug interactions, or clinical relevance. Its presence is only of interest in the context of gene family evolution, molecular genetics, and genomics research. Keratin 18 itself (the functional gene, not the pseudogene) is a well-established biomarker and regulator in certain cancers and epithelial cell biology[1]. This information is not applicable to KRT18P40, which is a non-functional pseudogene and not involved in these biological processes or disease mechanisms. In summary: KRT18P40 is a non-coding pseudogene and not a protein-coding therapeutic target, nor does it have biological, clinical, or pharmacological relevance[4][5].