CALCR and glioblastoma: Information available in the Human Protein Atlas (https://www.proteinatlas.org/CALCR/brain, accessed on 1 September 2023) and immunohistochemistry analyses indicate that the CTR expression occurs only in the hypothalamus, limbic system, and circumventricular organs in the brain stem in physiological conditions [40,109], but it is not expressed in the frontal and temporal lobe sites of GBM at the onset [41].