PDCD1 and malignant colon neoplasm: By modulating the TME, Andrographolide, the main bioactive component of TCM Andrographis paniculate, inhibits tumor growth (tumor weight of 1.57 g from 2.53 g) and induces apoptosis with an increase in infiltration and function of CD4 + and CD8 + T lymphocytes with increased tumor suppression cytokines, including interferon-γ (IFN-γ) (combination group vs. anti-PD-1 group:16.5 ± 1.7% vs. 10 ± 1.6%, P < 0.05), perforin, granzyme B, recombinant factor related apoptosis ligand (FasL), and TNF-α in colon cancer mouse models combined with anti-PD-1 [79].