It is our pleasure to inform you that the special issue, "Novel Biomarkers in the Immunotherapy Era" is now open for submissions.

Immunotherapy has become the standard treatment in many solid cancers, improving survival and response rate. However, long-term responses are achieved in only one third of patients treated with immune checkpoint inhibitors (ICIs). Some patients fail to respond to treatment or relapse after an initial response. So far, programmed death ligand 1 (PD-L1), microsatellite instability (MSI) and tumor mutation burden (TMB) are the three biomarkers that have been validated for predicting ICI response, but a single variable still seems insufficient for patient stratification. Given their substantial and increasing use, identifying novel predictive biomarkers for ICIs is critical. In this special issue, we welcome any research, case report or review describing novel potential biomarkers for patient selection for immunotherapy or novel combinations. Our aim in this Special Issue is to collect papers on advances in the field of translational validity of novel immune biomarkers in oncology, highlighting strengths and weaknesses of currently approved biomarkers, describing emerging tissue and circulating biomarkers and future perspectives.

Potential topics include, but are not limited to:

• Novel immunoregulatory agents;

• Novel biomarkers for the prediction of response to therapy;

• Novel tumour antigens;

• Immune escape and immune suppression mechanisms;

• Functional cross-talk between tumoral and immune cells within the tumoral microenvironment;

• Clinical and biological effects and limitations of immunotherapies;

• Metabolic and molecular mechanisms of immunotherapy resistance;

• Future perspectives for inhibitors of the immune checkpoint;

• New targets for combination with immunotherapy.

Keywords: Immunotherapy, biomarkers, translational research