BCL2 and neoplasm: Interestingly, two tumor-suppressive miRNAs, let-7 and miR-34, are the most common altered miRNAs in NSCLC tumor tissue The reduction in let-7 and miR-34 expression is relevant in the NSCLC oncogenic phenotype and is involved in the maintenance of oncogene addiction, via RAS, BCL2, MET or MYC.