CD274 and neoplasm: Patients with ≥ 6 months of PFS had a significantly higher (p = 0.013) percentage of tumour cells expressing PD-L1 (Fig. 2a) and a non-significantly lower sPD-L1 plasma concentration than patients with shorter PFS (16.34 pg/mL vs. 22.13 pg/mL, p = 0.0626, Fig. 2b).