CUL4B and lung cancer: These molecules act as scaffolding proteins for modular cullin RING ligase 4 (CRL4) complexes that promote the ubiquitination of a variety of substrates.22, 23, 24 Although accumulating research indicates that CUL4B expression is significantly elevated in various cancers including lung cancer,25, 26, 27, 28 the molecular mechanism of CUL4B up‐regulation remains unclear.