CUL4B and urinary bladder carcinoma: Intriguingly, AhR has been proposed to function as a Cullin 4B E3 ligase (CUL4B) adaptor, and in a recent study AhR was shown to recruit the CUL4B–RBX E3 ligase complex to the endoplasmic reticulum innate immune adaptor protein, stimulator of interferon genes (STING), leading to the proteasomal degradation of STING in bladder cancer cells (47).