In this paper we show, in silico, the role of miRNAs in the post-transcriptional
regulation of the onco suppressor gene PTEN by means of a (stochastic) competitive
model including interactions with miRNAs and other concurrent genes. The model
also covers protein formation and the mechanism going from the protein back to the
miRNAs. The numerical simulations confirm the biologically observed situation that the
increase of miRNAs concentration within the cell results in the lower expression of PTEN,
thus suggesting severe implications in brain tumorigenesis