To examine whether the decreased PD-L1 expression induced by miR-15a in PC cells may impact the cytotoxicity of CD8+ T cells, we co-cultured CD8+ T cells (effector cells) with DU145 or PC-3 cells (target cells) which overexpressed miR-15a and PD-L1. This evidence concerns the gene CD274 and pachyonychia congenita.