CD274 and neoplasm: Another category is biomarkers related to non-tumor cells, for example, tumor-infiltrating lymphocytes (TILs), circulating antigen-specific T cells, TLS,154 the microbiome, circulating L-arginine155 or L-alanine, PD-L1 expression on non-cancerous cells or platelets, and host factors such as the diversity of HLA gene types, gender, and smoking history.133