How can I obtain the genes "survived" to a filtering procedure? I do: mygenes <- genfilter(exprs(allgenes), filter) where filter is a general filterfunction I can check the number of survived genes by sum(mygenes) but how get names and relative expression data?? Thanks Edoardo -- "Raffiniert ist der Herr Gott, aber boshaft ist Er nicht." --- Dr. Edoardo Saccenti FiorGen Pharmacogenomics Foundation CERM Nuclear Magnetic Resonace Research Center Scientific Pole - University of Florence Via Luigi Sacconi n? 6 50019 Sesto Fiorentino (FI) tel: +39 055 4574193 fax: +39 055 4574253 saccenti@cerm.unifi.it www.cerm.unifi.it