The MSigDB Cancer Neighborhood  ontology contains gene sets from mining large collections of cancer-oriented microarray data. Each gene set is defined by correlated expression with one of 380 cancer-associated genes. 
Statistics can now be found in the footers of each table in the GREAT web output.
All ontology data was downloaded and built between Oct 14, 2011 and Feb 18, 2012.
GREAT v1.8 MSigDB Cancer Neighborhood statistics are available here.
GREAT v1.2 MSigDB Cancer Neighborhood statistics are available here.
Subramanian, A., et al. Gene set enrichment analysis: a knowledge-based approach for interpreting genome-wide expression profiles, Proc Natl Acad Sci U S A. 2005 Oct 25; 102(43):15545-50.
Brentani, H., et al. The generation and utilization of a cancer-oriented representation of the human transcriptome by using expressed sequence tags, Proc Natl Acad Sci U S A. 2003 Nov 11; 100(23):13418-23.