,33 Accordingly, cGAMP treatment of NK cell-derived leukemia cell line NKL and monocytic leukemia cell line THP-1 resulted in a dose-dependent increase of CD38 surface expression (Figures S2E and S2F), whereas a similar effect was not observed on ARK MM cells, suggesting that the response could be cell type-dependent. Here, CD38 is linked to monocytic leukemia.