**7. Biomarkers in immunotherapy**

Biomarkers are of significant importance in view that it predicts the clinical benefit to immunotherapy. Therefore, there is a need to bring into light several biomarkers in TNBC to distinguish that which patients is likely to get benefited from the ICIs or to build up certain therapies to overcome the hindrance in treating the respective malignancy. Until now PD-L1 was considered to be the major biomarker in TNBC. However, recent studies depicted that most of the mTNBC patients are PD-L1 negative arising the need to prospect into the immunotherapy field to find other novel biomarkers to get an insight into the patient responses to immunotherapy as a monotherapy or as a combinational therapy [50, 51]. Some of the biomarkers studied so far in TNBC include: TILs, TMB (tumor mutational burden), Gene signatures.
