The highest percentage and absolute number of apoptotic cells were detected on MB-MDA231 cells in T-/B-cell/tumor coculture systems in which CD19+ B cells were stimulated by LPS among the other groups, and the percentages of apoptotic cells were decreased in the coculture experiment in which CD19+ B cells were stimulated by sPD-L1 (Figure 6B). Here, SPDL1 is linked to neoplasm.