This invention provides for a cDNA that is a coding region of a previously
unknown member of the ETS transcription regulator family. The gene
described herein (designated ESX) is located at chromosome 1q32 a region
amplified in 50% of early breast cancers. The ESX gene of this invention
is associated with the etiology of various cancers including breast
cancers. Detection of the ESX gene or gene product is thus of diagnostic
and/or prognostic value.