CD274 and neoplasm: A higher serum sIL-2R level (median: 498.8), higher serum PD-L1 level (median: 27.0), higher pAkt(Ser-473) expression (median: 5.63), undifferentiated tumor histology, and regional lymph node metastasis were all associated with shorter overall survival according to Cox univariate analysis, but only sIL-2R and PD-L1 were confirmed to have an impact by multivariate analysis (Table 3).