Figure 2.

IDO1 expression is associated with immune‐related gene expression and immune cell infiltrates in PSCC. Pearson's correlation analysis between the mRNA levels of IDO1 and the mRNA levels of immune‐related gene PD‐1, CTLA‐4, PD‐L1, and PD‐L2 (A) and the infiltration of CTL, Treg, TAM and MDSC (B), defined by a principal component analysis of the corresponding signature marker genes in PSCC. Abbreviations: IDO1, Indoleamine 2,3‐dioxygenase 1; PSCC, penile squamous cell carcinoma; PD‐1, programmed cell death protein‐1; CTLA‐4, cytotoxic T lymphocyte‐associated protein 4; PD‐L1, programmed death‐ligand 1; PD‐L2, programmed death‐ligand 2; CTL, cytotoxic T lymphocyte; Treg, regulatory T lymphocyte; TAM, tumor‐associated macrophage; MDSC, myeloid‐derived suppressor cell