Nevertheless, some clinical signs could be related to RCC, such as polycythemia, hypercalcemia, hypertension, and Cushing’s syndrome, correlated to erythropoietin, parathyroid-related hormone, renin, and adrenocorticotropic hormone (ACTH) overproduction by cancer, respectively. This evidence concerns the gene REN and Cushing syndrome due to macronodular adrenal hyperplasia.