PPI

PPI may refer to:

Biochemistry

PP_i, the anion P₂O₇⁴⁻, a pyrophosphate
PPI, peptidylprolyl isomerase, a human chaperone (protein)
PPI, a right-handed form of polyproline helix, a secondary structure in proteins
PPI, Protein–protein interaction frequently referring specifically to the network of interactions between a subset of proteins in a living cell.

Pareto priority index, an index to prioritize projects
Plan Position Indicator, a display of tactical information from RADAR or other sources.
Producer Price Index, a metric used in economics, related to inflation

Patient package insert, a document included with certain prescription medications
Prepulse inhibition, the ability of the nervous system to attenuate the startle response when a warning stimulus is given
Proton-pump inhibitor, a drug that reduces gastric acid secretion in the stomach
Psychophysiological Interaction, an analysis technique for identifying task-related functional connectivity between brain regions

Italian People's Party (1919) (Partito Popolare Italiano), precursor of the Christian Democracy party
Italian People's Party (1994) (Partito Popolare Italiano), one of the successor parties of Christian Democracy
Peace Party of India, Indian political party in the state of Uttar Pradesh
Philips Phonographische Industries, the original name for Philips Records
Phonographic Performance (Ireland) Limited
Pirate Party (Iceland)
Pirate Parties International, umbrella organization of the international Pirate Party movement
Polly Peck International, a British diversified company bankrupt and broken up since 1990
Primarily Primates, an animal sanctuary for non-human primates in Texas, United States.
Professionals Party of India, an Indian political party registered with the Election Commission of India
Progressive Policy Institute, a U.S. public policy think tank

Parallel Peripheral Interface, a connection for driving LCD displays on processors such as the Blackfin
Gabarit passe-partout international, or the Berne gauge, a structure clearance standard in European railways
Picks per inch, a unit of textile measurement
Pixels per inch, the pixel density of devices such as computer displays, image scanners, and digital cameras
Plan position indicator, a map-like display on a cathode ray tube device for radar applications
Per-Packet Information, variety of Pcap file used in computer network analysis