1. What is a "gene expression signature" for a tumor?

A collection of genes that are expressed consistently higher or lower in the tumor than is the population norm for non-tumorous tissue of the same type.

2. What are the benefits of high-throughput expression analysis in molecular biological investigations?

These techniques allow simultaneous analysis of the expression of many genes. Patterns of increased or decreased expression is associated with disease may then be identified and may contribute to improved diagnosis and prognosis.