[BioC] restrict transcriptDB object to "known" genes

[Stefanie]

Dear list,

I would like to retrieve genomic ranges via makeTranscriptDbFromUSCS.
At the moment I just use:

humanDB = makeTranscriptDbFromUSCS(genome = "hg19", tablename = "ensGene")

Is there an automatic way to restrict my humanDB to those genes that a "known"
status (not novel)?

best,
stefanie