I'm starting to use TCGA data. Level 3 data SNP data determining CNV have the following format:
The TCGA consortium includes segments with very small segment means (e.g. 0.02, line 3 above), but a large number of involved probes (e.g. 7302, line 3 above). Does anyone have any opinion on how to interpret these? Such a large number of involved probes makes me think they're more than noise, but the small segment mean suggests there's barely an increase in this segment. Does it represent a subclone comprising a small fraction of the tumor?