Blobel, Günter (BLOH buhl) (1936-) is a German-born American cell biologist who won the 1999 Nobel Prize in physiology or medicine for discovering how newly made proteins find their correct locations within a cell. His discoveries have shed light on the causes of several diseases.

Blobel earned his M.D. degree at the University of Tübingen in 1960 and his Ph.D. degree in oncology at the University of Wisconsin at Madison in 1967. He then joined the cell biology laboratory of Nobel laureate George Emil Palade at Rockefeller University. In 1976, he became a full professor at Rockefeller.

In 1971, Blobel suggested that newly made proteins in the body carry special signals that direct them to their proper locations and roles. These new proteins continually replace the dying proteins within cells. Blobel determined the steps in sorting and transporting proteins and then figured out the principles that govern the process. His later research focused on the process that determines whether a protein will exit a cell, build up a cell wall, or enter an organelle, a specialized compartment within a cell. Blobel's discoveries proved true for proteins in all living things.

Blobel's research traced certain hereditary diseases to mistakes in the signals and led other scientists to transform cells into protein factories by altering them slightly. The altered cells can produce insulin, for example, or a substance that encourages bone marrow production.

Blobel now heads Rockefeller University's cell biology laboratory. His work on the accurate distribution of proteins sheds light on AIDS, cystic fibrosis, and Alzheimer's research, and his research on proteins in the human genome map is expected to illuminate disease-causing processes and suggest new therapies.