Cerqueira MA, et al. - Through a first study prospective observational study, a total of 240 sextant prostate biopsies cores (12 cores/patient) were taken from 10 unilateral prostate cancer patients by the experts in order to determine the T cell infiltrate pre- and post-cryoablation. Cancer-positive (Diag+) and cancer-negative (Diag-) lobes at diagnosis and the same areas 12 months post-hemi-cryoablation (Cryo+ and Cryo-, respectively) were examined by immunohistochemistry for infiltrating CD4+ and CD8+ T cells. In comparison to Diag+ tissue, a makred elevation in tumor-infiltrating CD8+ T cells/mm² in the Cryo+ tissue was observed which was approved in prostate acini (hot spots) in which infiltrating CD4+/CD8+ T cells’ ratio decreased post-hemi-cryoablation. Infiltrating CD4+ T cells/mm² exhibited a trend to diminish in Cryo+ when contrasted with Diag+. This was the first study to portray local immune modulation post-prostate cancer cryoablation, characterized by diminishing CD4+/CD8+ T cells’ ratio, the potential for clinical effects by exhibiting the T-cell response to cancer. Hence, to assess various energies and longer follow-up clinical endpoints, future studies are important.