Cancers can suppress the immune system through various mechanisms. One way is by secreting certain immunosuppressive substances, such as cytokines, that inhibit the activity of immune cells. Additionally, cancer cells can express inhibitory molecules like PD-L1 that bind to receptors on T-cells, effectively "turning off" these immune cells. Another method is by creating an immunosuppressive microenvironment, which includes regulatory T-cells and myeloid-derived suppressor cells that further dampen immune responses.
