CD274 and undifferentiated (embryonal) sarcoma: Specifically, Pt.1 grade III myxofibrosarcoma and Pt.2 undifferentiated sarcoma showed the lowest HLA-I (MFI = 52 and 124) and positivity for PD-L1 in 60 and 75% of cells, respectively, whereas grade I Pt.3 and Pt.4 showed the highest expression of HLA-I (MFI = 915 and 579) and positivity for PD-L1 in 0.5 to 22% of cells, respectively.