PGR and neoplasm: In summary, estrogen inhibits colorectal cancer liver metastasis via TNF receptor-2, reverses extracellular vesicle-mediated immunosuppression of the tumor microenvironment on colorectal cancer growth in mice, inhibits colorectal cancer tumor growth via down-regulation of PD-L1 expression and M1 macrophages, and progesterone receptor antagonists inhibit colorectal cancer liver metastasis by modulating NK cells.