Three researchers have won the 2013 Nobel Prize for medicine for their work into how the cell organises its transport system.
Two Americans, James Rothman and Randy Schekman, and Germany's Thomas Sudhof were also awarded a prize of €883,000.
"Through their discoveries, Rothman, Schekman and Sudhof have revealed the exquisitely precise control system for the transport and delivery of cellular cargo," the Nobel Assembly at Sweden's Karolinska Institute said in a statement.
Medicine is the first of the Nobel Prizes awarded each year.
Cells are factories that produce and export molecules, such as insulin and neurotransmitters.
The molecules are transported around the cell in small packages called vesicles.
Until recently, it remained a mystery how the right substances were delivered to the right places at the right time.
If cells were not organised in such a precise way, they would lapse into chaos.
Defective vesicle transport occurs in a variety of diseases, including a number of neurological and immunological disorders, as well as in diabetes.
Professor Schekman of the Department of Molecular and Cell biology at the University of California at Berkeley, discovered a set of genes that were required for vesicle traffic.
Professor Rothma of the Department of Cell Biology at Yale, unravelled protein machinery that allows vesicles to fuse with their targets to permit transfer of cargo.
German-born Professor Südhof - Molecular and Cellular Physiology at Stanford University - revealed how signals instruct vesicles to release their cargo with precision.
The Nobel Foundation said that through their discoveries, the three men have revealed the precise control system for the transport and delivery of cellular cargo.
Disturbances in this system have deleterious effects and contribute to conditions such as neurological diseases, diabetes and immunological disorders.
Prizes for achievements in science, literature and peace were first awarded in 1901 in accordance with the will of dynamite inventor and businessman Alfred Nobel.