With the denomination of 'non-coding RNA' we identify those RNA molecules which are functional but that are not translated into proteins. Many microarray chips contain probes that are annotated as 'non-protein coding', indicating that there might be some valuable expression data that we can also mine for information. We note that our method, although employing transcriptomic data, does not limit its application to proteincoding information, and that the combined use of protein-coding and non-coding protein probe expression would allow a more comprehensive view of the transcriptional state of the cell.