- Plasma cells from multiple myeloma patients express B7-H1 (PD-L1) and increase expression after stimulation with IFN-{gamma} and TLR ligands via a MyD88-, TRAF6-, and MEK-dependent pathway. Liu, J., Hamrouni, A., Wolowiec, D., Coiteux, V., Kuliczkowski, K., Hetuin, D., Saudemont, A., Quesnel, B. Blood (2007)