In addition, a systematic review on the diagnosis of GHD as a late effect of radiotherapy in survivors of childhood cancer raises the question on how to interpret the GH response after GHRHarg in patients with primary hypothalamic dysfunction (8) with a recommendation against the use of GHRH alone or in combination with arginine after hypothalamic–pituitary axis radiation. The gene discussed is GH1; the disease is childhood malignant neoplasm.