Colleagues, I think this should be pretty simple task but I cannot find an appropriate package for that. I need to generate a subset of eSet object which contains certain probesets indicated in an external genelist (outside R environment). I.e. this procedure should look like this: mylist <- read.table ..... fltered.eset <- someFunction(eSet, mylist) Probably this is already implemented somewhere. Any hints will be appreciated. All the best, Oleg