MKI67 and cancer: To check if the correlation between decreased proliferation and promotion of NED is also observed in vivo in human cancer tissue, we examined the expression of NED markers γ-enolase and chromogranin A and the proliferation marker Ki-67 by immunohistochemical examination of formalin-fixed paraffin-embedded tissue samples from 18 patients with advanced prostate adenocarcinoma (patients information Additional file 4: Table S3; subset of patients with lymph node metastases was selected in order to obtain a higher percentage of NED for evaluation).