CD274 and neoplasm: Remarkably, recent studies have found intrinsic PD-1 expression in tumor cells, and PD-1 additionally induces PD-L1 expression in tumor cells through cross-reactive stimulation in the tumor microenvironment, which promotes tumor cell growth and migration.28 Therefore, we confirmed cell growth and migration after silencing of both PD-1 and PD-L1 in TC-1 tumor cells.