A detailed atlas of the deadliest form of brain cancer promises to be a valuable tool for both diagnosis and drug development.

Glioblastoma tumours are notoriously aggressive and difficult to remove surgically. Ralph Puchalski at the Allen Institute for Brain Science in Seattle, Washington, and his colleagues examined 42 such tumours using a technique called laser microdissection. This method allowed them to isolate anatomical regions of each tumour, such as its border and clusters of living cells surrounding patches of dead tissue. The researchers then analysed RNA sequences and gene expression for each of those regions, generating a map that the team named the Ivy Glioblastoma Atlas.

The map revealed genes whose expression varies according to a cell’s location within the glioblastoma. Other teams have already used the data to study potential drug targets.