The percentage of PD-1-expressing CD8 + tumor-infiltrating cytotoxic lymphocytes also decreased from 22,03 ± 2,66% in Nav1.8-Cre−/hM3Dq+ to 12.99 ± 3.85% in Nav1.8-Cre+/hM3Dq+ animals (Fig. 5E), while the expression of CTLA-4 did not vary in these cells (Fig. 5D, F). Here, PDCD1 is linked to neoplasm.