Originally, Watson was drawn into molecular biology by the work of Salvador Luria. Luria eventually shared the 1969 Nobel Prize in Physiology or Medicine for his work on the Luria–Delbrück experiment, which concerned the nature of genetic mutations. He was part of a distributed group of researchers who were making use of the viruses that infect bacteria, called bacteriophages. He and Max Delbrück were among the leaders of this new "Phage Group," an important movement of geneticists from experimental systems such as "Drosophila" towards microbial genetics. Early in 1948, Watson began his PhD research in Luria's laboratory at Indiana University. That spring, he met Delbrück first in Luria's apartment and again that summer during Watson's first trip to the Cold Spring Harbor Laboratory (CSHL).