IRF4 and neoplasm: Most of them were overexpressed in tumor-infiltrating Tregs, and included co-stimulatory and inhibitory molecules (e.g., 4-1BB, OX-40, BTLA, PD1, GITR, PD-L1, Tim-3, B7-H3, and LAG-3), chemotactic molecules (CCL20, CCL22, CX3CL1, CXCL5, CX3CR1, CXCR3, and CD200), cytokines and receptors (IL27, TNF-α, IFN-γ, IL1-R1, LTβR, and IL1-R2), transcription factors (IRF4, STAT4, and FoxA1), immunosuppression molecules (IL-10, CD39, and GARP), and cytotoxic molecules (granzyme B, granulysine (GNLY), and FasL).