org.EcK12.egALIAS2EG {org.EcK12.eg.db} | R Documentation

## Map between Common Gene Symbol Identifiers and Entrez Gene

### Description

org.EcK12.egALIAS is an R object that provides mappings between common gene symbol identifiers and entrez gene identifiers.

### Details

Each gene symbol maps to a named vector containing the corresponding entrez gene identifier. The name of the vector corresponds to the gene symbol. Since gene symbols are sometimes redundantly assigned in the literature, users are cautioned that this map may produce multiple matching results for a single gene symbol. Users should map back from the entrez gene IDs produced to determine which result is the one they want when this happens.

Because of this problem with redundant assigment of gene symbols, is it never advisable to use gene symbols as primary identifiers.

This mapping includes ALL gene symbols including those which are already listed in the SYMBOL map. The SYMBOL map is meant to only list official gene symbols, while the ALIAS maps are meant to store all used symbols.

Mappings were based on data provided by: Entrez Gene ( ftp://ftp.ncbi.nlm.nih.gov/gene/DATA ) on 2008-Sep2

### References

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=gene

### Examples

        # Convert the object to a list
        xx <- as.list(org.EcK12.egALIAS2EG)
        # Remove pathway identifiers that do not map to any entrez gene id
        xx <- xx[!is.na(xx)]
        if(length(xx) > 0){
            # The entrez gene identifiers for the first two elements of XX
            xx[1:2]
            # Get the first one
            xx[[1]]
        }

[Package org.EcK12.eg.db version 2.2.6 Index]