The present invention relates to a method for suppressing or treating cancer, in particular to a method for suppressing or treating one or more of colorectal cancer, breast cancer, prostate cancer and/or lung cancer. The therapy employs use of a non-cytotoxic protease, which is targeted to a growth hormone-secreting cell such as to a pituitary cell. When so delivered, the protease is internalized and inhibits secretion/transmission of growth hormone from said cell. The present invention also relates to polypeptides and nucleic acids for use in said methods.
