Recently, the sex determining region Y ( Sry) and the cerebellar 
degeneration-related protein 1 ( CDR1as) RNA transcripts have been described to 
function as a new class of post-transcriptional regulatory RNAs that behave as 
circular endogenous RNA sponges for the micro RNAs (miRNAs) miR-138 and miR-7, 
respectively. A special feature of the Sry gene is its ability to generate 
linear and circular transcripts, both transcribed in the sense orientation. Here 
we remark that both sense (e.g. Sry RNA) and antisense (e.g. CDR1as) transcripts 
could circularize and behave as miRNAs sponges, and importantly, that also 
protein-coding segments of mRNAs could also assume this role. Thus, it is 
reasonable to think that the linear Sry sense transcript could additionally act 
as a miRNA sponge, or as an endogenous competing RNA for miR-138.