Clear cell RCC tumor tissues from 83 patients (Table 1) who underwent nephrectomy were processed by immunohistochemistry in Tissue Micro Array (TMA) for pro-BDNF/BDNF (both mature and immature forms recognized by a common antibody), pro-BDNF alone, as well as p75NTR, TrkB receptor or sortilin. The gene discussed is BDNF; the disease is neoplasm.