Yet another type of immunotherapy uses proteins that normally help regulate, or modulate, immune system activity to enhance the body’s immune response against cancer. These proteins include cytokines and certain growth factors.Two types of cytokines are used to treat patients with cancer: interleukins and interferons.et another type of immunotherapy uses proteins that normally help regulate, or modulate, immune system activity to enhance the body’s immune response against cancer. These proteins include cytokines and certain growth factors.