== What is a "RNA gene"? == 

 Is the statement, "Nuclear genome contains c.a. 3000 RNA genes (less than 10% of total gene number)." true?   

 According to the FANTOM project, only 17,594 of the 33,409 transcriptional units were determined to have coding potential.  As a result, all remaining units have the potential to be puative ncRNAs [Okazaki et al. (2002) Nature 420:563-573; Suzuki and Hayashizaki (2004) Bioessays 26:833-843].  A very recent estimate suggests that there may be at least 28,000 ncRNAs within the FANTOM library [Liu et al. (2006) PLoS Genet 2:529-536].  Another estimate has put the percentage, at least in humans, at around 98% [Mattick (2001) Embo Rep 2:986-991]. 

 What exactly are you defining as an "RNA gene" in this statement?