Soluble chromatin was prepared from 3×106 cells and precipitated with anti-MYC, anti-NF-κB p65 (Santa Cruz Biotechnology), anti-MUC1-C or a control nonimmune IgG. Power SYBR Green PCR Master Mix (Applied Biosystems) and ABI Prism Sequence Detector (Applied Biosystems) were used for amplification of ChIP qPCRs. Primers used for qPCR of the PD-L1 promoter and GAPDH control region are listed in Supplementary Table S2. Relative fold enrichment was calculated as described (26 (link)).