While PD-L1 mostly affects the interaction between tumor cells and T cells, increasing evidence suggests that intrinsic PD-L1 signaling may impact the proliferation and survival of tumor cells.28 However, within our experimental setup, stimulation of HT-29 cells with ADP-heptose, while increase PD-L1 expression, did not affect the proliferation of the cells (Figure S6). Here, CD274 is linked to neoplasm.