CCND1 and lung cancer: Our present study has revealed the following novel findings: (i) exogenously overexpressed miR-134 suppresses tumor regeneration in 6 lung cancer xenograft models and inhibits cell growth in vitro and in vivo; (ii) miR-134 overexpression inhibits NSCLC cells migration and invasion; (iii) inhibition of miR-134 in NSCLC cells results in high clonal, clonogenic, and tumorigenic properties; (iv) miR-134 overexpression promotes NSCLC cells apoptosis, and inhibition of miR-134 inhibits NSCLC cell apoptosis; (v) miR-134 targets CCND1 in NSCLC cells and negatively expressed with CCND1.