Dear list, I am having a set of human oligo ids (H200006022 H200002025 H300004703 H200000442 H200005719 H300018350) which I want to map to Ensembl or RefSeq. I am sure R has a function to do that. I downloaded the {oligo} package and tried to use the probeNames function. Although the factor of ologo ids is an object (as the argument to probeNames should be) I retrieve the following error: probeNames(significant_genes[,1]) Error in function (classes, fdef, mtable) : unable to find an inherited method for function "probeNames", for signature "factor" where significant_genes is the factor with the oligo ids. Could anyone help me with the format I should use in order to apply probeNames? Or if someone has any other function in mind which can do the mapping I would be really grateful to hear that. Thank you all, Eleni [[alternative HTML version deleted]]