INHBE and colorectal carcinoma: These data provide evidence that (i) stage-specific effects in CRC tissue are activin-dependent, (ii) activin stimulates the PI3K pathway to promote tumor cell proliferation and expression of immunosuppressive markers, (iii) activin activates the MAPK pathway to support immunosuppression, and (iv) mediates macrophage and fibroblast interactions to facilitate metastasis.