Additionally, cytometric analysis for programmed cell death protein 1 (PD1), programmed death-ligand 1 (PDL1), and cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) was also performed; a study seldom investigated for angiosarcomas but may have advantages over immunohistochemical analysis. The gene discussed is PDCD1; the disease is angiosarcoma.