USP5 promotes the proliferation and migration of NSCLC cells by binding to CCND1, reducing polyubiquitin-mediated degradation of CCND1 and stabilising its protein levels. KRAS activates USP5 to stabilise nuclear Beclin 1, leading to instability of MDM2-mediated p53 protein. Here, MDM2 is linked to non-small cell lung carcinoma.