When the immune system is functioning normally, immune cells move around the body
looking for things that don’t belong, like bacteria and viruses. These immune cells search
for invaders using “receptors”. When receptors find invaders in the body, special immune
cells come in to destroy them; these cells are called cytotoxic T cells.
Unfortunately, cancer cells are often able to hide from immune cells, which is why the
cancer cells can grow out of control. Immunotherapy is a cancer treatment intended to
make the body’s immune system able to detect and destroy cancer cells. Immune
checkpoint inhibitors have been a successful immunotherapy approach because it pushes
the immune system into high gear to fight cancer.