There are three principal directions in which biomarkers might be investigated: tumour tissue‐derived biomarkers (mutation load, microsatellite instability, gene signatures), tumour microenvironment‐based biomarkers (PD‐L1, LAG‐3 expression or presence of tumour infiltrated lymphocytes) and biomarkers associated with the host (microbiome and peripheral blood biomarkers). Here, LAG3 is linked to neoplasm.