Note: If you are using Excel to edit GenePattern files, be sure to save the file as a tab-delimited text file and supply the correct file extension. You can specify the file name in quotes to prevent Excel from appending .txt to the file name. Also, note that Excel's auto-formatting can introduce errors in gene names, as described in Zeeberg, et al (2004).
GRP File Format
The GRP file format contains a single gene set in a simple newline-delimited text format. Typically, you use the GMT or GMX file formats to create gene sets, rather than using the GRP file format. The GRP format contains a line for each gene, one gene per line. Lines that start with a pound sign (#) are ignored.