PTEN and lung adenocarcinoma: Unique miRNA profiling studies demonstrated that lung adenocarcinoma or SqCC presented higher miR-155 expression levels compared to normal tissues and suggested that its oncogenic role [34] is possibly related to direct inhibition of tumor suppressors, PTEN, and the suppressors of cytokine signalling 1 and 6 (SOCS1 and SOCS6) [36].