FIGURE 1.

Potential predictive biomarkers of response for antitumor immunotherapy. Biomarkers could be found from tumor tissue biopsy samples, peripheral blood, and gut microbiome. Biomarkers isolated from tumor biopsy mainly include PD‐L1 expression, TMB, driver gene mutation, oncogenic signaling, and epigenetic regulation. Peripheral blood biomarkers include immune cells (such as T, B, NK, DCs, MDSCs, and Treg cells) and solute markers (such as ctDNA, soluble PD‐L1). Gut microbiome is also a promising predictor for immunotherapy. PD‐L1, programmed cell death ligand‐1; CTLA‐4, cytotoxic T‐lymphocyte antigen‐4; TMB, tumor mutation burden; HLA, human leukocyte antigen; ctDNA, circulating tumor DNA; bTMB, blood‐based tumor mutation burden; NK cells, natural killer cells; DCs, classical dendritic cells; MDSCs, myeloid‐derived suppressor cells; Treg, regulatory T; TCR, T cell receptor; MHC, major histocompatibility complex (www.home‐for‐researchers.com).