CD274 and cancer: Recently, it has been demonstrated that phosphorylation of PD-L1 at Thr285 and Thr290 by CK2 disrupted PD-L1 binding with speckle-type POZ protein and protected PD-L1 from cullin 3 ubiquitin E3 ligase complex-mediated proteasomal degradation in cancer and DC [322].