Hi,

Could someone give me the definition of LOC# identifiers and where can I found it? I cannot find any place with the criteria to give to a gene an identifier such as LOC#.

Thanks!
From the <a href="http://www.ncbi.nlm.nih.gov/books/NBK3840/#genefaq.Conventions">NCBI book</a>:

> **Symbols beginning with LOC.** When a published symbol is not available, and orthologs have not yet been determined, Gene will provide a symbol that is constructed as 'LOC' + the GeneID. This is not retained when a replacement symbol has been identified, although queries by the LOC term are still supported. In other words, a record with the symbol LOC12345 is equivalent to GeneID = 12345. So if the symbol changes, the record can still be retrieved on the web using LOC12345 as a query, or from any file using GeneID = 12345.