Hi, I did analysis of some public available microarray data sets (available as .cel files), then mapped the affymatrix probe IDs to EnsEMBL ID by EnsMart. I am interested in whether some genes are present or absent (binary) in given samples. I have a question: if several different probes reprenting the same gene have the different P/M/A calls, are there any strategies for determing whether the gene is present or absent in the sample? Wuming