\HeaderA{org.Hs.egSYMBOL}{Map between Entrez Gene Identifiers and Gene Symbols}{org.Hs.egSYMBOL}
\aliasA{org.Hs.egSYMBOL2EG}{org.Hs.egSYMBOL}{org.Hs.egSYMBOL2EG}
\keyword{datasets}{org.Hs.egSYMBOL}
\begin{Description}\relax
org.Hs.egSYMBOL is an R object that provides mappings between
entrez gene identifiers and gene abbreviations.
\end{Description}
\begin{Details}\relax
Each entrez gene identifier is mapped to the a common abbreviation for 
the corresponding gene. An \code{NA} is reported if there is no known
abbreviation for a given gene.

Symbols typically consist of 3 letters that define either a single
gene (ABC) or multiple genes (ABC1, ABC2, ABC3). Gene symbols can be
used as key words to query public databases such as Entrez Gene.

Mappings were based on data provided by: Entrez Gene ( ftp://ftp.ncbi.nlm.nih.gov/gene/DATA ) on 2008-Apr2
\end{Details}
\begin{References}\relax
\url{http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=gene}
\end{References}
\begin{Examples}
\begin{ExampleCode}
        x <- org.Hs.egSYMBOL
        # Get the gene symbol that are mapped to an entrez gene identifiers
        mapped_genes <- mappedkeys(x)
        # Convert to a list
        xx <- as.list(x[mapped_genes])
        if(length(xx) > 0) {
          # Get the SYMBOL for the first five genes
          xx[1:5]
          # Get the first one
          xx[[1]]
        }
        # For the reverse map:
        x <- org.Hs.egSYMBOL2EG
        # Get the entrez gene identifiers that are mapped to a gene symbol
        mapped_genes <- mappedkeys(x)
        # Convert to a list
        xx <- as.list(x[mapped_genes])
        if(length(xx) > 0) {
          # Get the entrez gene ID for the first five genes
          xx[1:5]
          # Get the first one
          xx[[1]]
        }
\end{ExampleCode}
\end{Examples}

