Peptidylprolyl isomerase A pseudogene 66 (PPIAP66)

Peptidylprolyl isomerase A pseudogene 66 (PPIAP66) is a human pseudogene, meaning it is a genomic DNA sequence resembling the functional gene *PPIA* (Peptidylprolyl isomerase A, encoding Cyclophilin A) but has lost the ability to encode a functional protein product due to disabling mutations or lack of necessary regulatory elements[1][5][7]. Pseudogenes like PPIAP66 are generally non-functional and are not considered therapeutic targets or relevant biomarkers in medicine. While some pseudogenes may participate in gene regulation by acting as competing endogenous RNAs or sources of small RNAs in rare contexts, there is currently no evidence that PPIAP66 performs such functions[2][5]. Colloquially, the functional gene PPIA (Cyclophilin A) is an enzymatically active peptidyl-prolyl isomerase involved in protein folding and is a drug target, but PPIAP66 is not[4][3]. This gene is annotated as a pseudogene in major genetic databases and lacks protein-coding potential[1][7][5]. There are no reported drugs, mechanisms of action, biomarker roles, or clinical safety considerations for PPIAP66. If you are seeking information on the **active, therapeutic target** related to "Peptidylprolyl isomerase A," refer instead to the gene/protein **PPIA (Cyclophilin A)**, which is an enzyme and cyclosporin A-binding protein of significant physiological and pharmacological relevance[3][4]. PPIAP66 is not a receptor, enzyme, or therapeutic target.