This suggests that the percent of regulatory T cells present in the tumor may be a determining factor in limiting the proliferation of T cells in vitro. PD-L1 expression by itself did not correlate with the ability to culture TIL, however, when we took the ratio of CD8+ T cells to PD-L1+ cells, there was an increased trend(P = 0.09) (Fig. 4c-d), suggesting a potential contributory immunosuppressive roles for PD-L1 in preventing the generation of TIL in vitro. Here, CD8A is linked to neoplasm.