NT5C and neoplasm: Four hours after dosing, we found that 2 μg CDN treatment resulted in widespread phosphorylation of TBK1 (pTBK1) in CD19 positive B cells as well as APCs suggesting uptake of the CDN and broad activation of the STING pathway in both tumor and immune cells, whereas 0.02 μg exoSTING induced pTBK1 expression selectively in subset of immune cells that are CD19 negative (Fig. 7a, top row).