Immune checkpoint inhibition to activate the immune system has emerged as an exciting treatment option for several cancers. Programmed death-ligand 1 (PD-L1) plays a major role in immune suppression. We investigated the relationship between the aberrant choline metabolism observed in most cancers and PD-L1 expression in triple negative human MDA-MB-231 breast cancer cells. Using siRNA to downregulate choline kinase-α (Chk-α) or PD-L1 or both, we identified a close inverse interdependence between Chk-α, PD-L1 and phosphocholine. These results have significant implications for treatments that decrease Chk-α expression as these may drive up PD-L1 expression allowing escape of cancer cells from immune surveillance.