With equipment designed to probe the smallest segments of the genetic code, researchers at Dana-Farber Cancer Institute and collaborating institutions have found something much larger: sections of the chromosomes of lung cancer cells where cancer-related genes may lurk. In a study in the July 1 issue of the journal Cancer Research, the researchers used single nucleotide polymorphism (SNP) array technology, which focuses on the building blocks of individual genes, to identify regions of chromosomes where genes were either left out or multiplied over and over – mistakes that are often associated with cancer. In this effort, SNP (pronounced “snip”) arrays have been used to find gene-copy errors in lung cancer cells.