Indeed, PTEN is the paradigm for a new mechanism of posttranscriptional regulation exerted by competitive endogenous RNAs (ceRNAs), which are co-regulated with other transcripts bearing common microRNA recognition elements.15, 16 In lung adenocarcinoma, although PTEN inactivation by mutation is rare,17 loss of PTEN expression is not uncommon and has been attributed to both epigenetic18 and posttranscriptional19 mechanisms. This evidence concerns the gene PTEN and lung adenocarcinoma.