CD274 and neoplasm: T cells recognize tumor cells in the human body and kill them, but when tumor cells recognize PD1 protein on T cells, the tumor cells will upregulate the PDL1 protein and PD1 binds to PDL1 leading to apoptosis of the T cells (Li et al., 2015; Topalian et al., 2016; Tremblay et al., 2018; Li et al., 2020).