NCG allows retrieving information on cancer genes in three ways: (i) by using different types of identifiers, such as gene symbols, Entrez IDs (39), RefSeq (40) or Ensembl IDs (29), for specific genes or groups of genes of interest; (ii) by selecting precompiled lists of cancer genes; and (iii) by combining different criteria to analyze genes with similar duplicability, orthology and network properties. The primary output of the query is a summary table that provides links to several external databases, such as Entrez (www.ncbi.nlm.nih.gov/Entrez/), HPRD (http://www.hprd.org/), OMIM (http://www.ncbi.nlm.nih.gov/omim/) (41), RefSeq (http://www.ncbi.nlm.nih.gov/RefSeq/) and Ensembl (http://www.ensembl.org/), as well as to detailed reports on duplicability, orthology and network properties.
