In the Affymetrix annotation file, I find that some probe set ID are mapped to multiple genes separated by '///', such as 200012_x_at is mapped to RPL21P16///RPL21P119///RPL21. How to handle this case?
Depends what you want to do with the array data?
I need do GSEA analysis. So is there a general way to handle this case?
i suggest you to use this database