Examples are cetuximab in multimodal radio-chemotherapy regimens for rectal cancer [115-119] or erythropoietin, which was thought to increase the haemoglobin level in head-and-neck cancer patients, but decreased survival most likely due to EPO-receptors on the cancer cells which were not known as a proliferative factor for tumours before [120,121]. This evidence concerns the gene EPO and rectal cancer.