CD274 and central nervous system cancer: In another study containing 174 human glioma specimens, Clone 5H1 showed that 70.1% of all specimens was diffuse/fibrillary PD-L1-positive (>25% of the tumor cells was PD-L1+), and 40.8% of all specimens was PD-L1+ on cell membranes (Berghoff et al., 2017).