[4][7][8][9][10] Due to its various functions, PPIA has been implicated in a broad range of inflammatory diseases, including atherosclerosis and arthritis, and viral infections.

PPIases catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and accelerate protein folding.

[10] In particular, PPIA is predominantly expressed in the nucleus and cytoplasm of the cell, where it partakes in intracellular signaling, protein transport, and transcription regulation.

[7][8][9][10][11] In hemopoietic cells, subcellular localization of PPIA from the nucleus to the cytoplasm has been observed during c-Jun N-terminal kinase- and serine protease-dependent microtubule disruption.

This localization has been correlated with G2/M arrest, indicating that the protein's PPIase function may be regulated by microtubule dynamics during the cell cycle.

[8][9][11][14] PPIA may also activate Akt and NF-κB signaling, resulting in the upregulation of Bcl-2, an antiapoptotic protein, and thus preventing apoptosis in ECs in response to oxidative stress.

In later stages of apoptosis the entire cell becomes fragmented, forming a number of plasma membrane-bounded apoptotic bodies which contain nuclear and or cytoplasmic elements.

The ultrastructural appearance of necrosis is quite different, the main features being mitochondrial swelling, plasma membrane breakdown and cellular disintegration.

As a proinflammatory cytokine, PPIA is highly involved in acute and chronic inflammatory diseases, including sepsis, atherosclerosis, and rheumatoid arthritis.