Table 1 Selected factors/biomarkers of response and resistance to ICIs

Tumor mutational burden (TMB)

Myeloid-derived-suppressor cells (MDSCs)

Neoantigen expression

Tumor-associated macrophages (TAMs)

High levels of microsatellite instability (MSI-H)

Regulatory T cells (Tregs)

Deficient mismatch repair (dMMR)

Extracellular matrix (ECM)

Tumor-infiltrating lymphocytes

Collagen

Inflammation gene signature

Cancer-associated fibroblasts (CAFs)

PD-L1 expression

Transforming growth factor-beta (TGF-β)

LAG-3 expression

Host factors (Microbiome)