First, the inhibition of the dipeptidylpeptidase DPP4 dampens the CXCL10 degradation, thus improving the CD4 and CD8 T-cell recruitment and limiting the melanoma and colon tumor growth in the presence or not of anti-PD-1 and/or anti-CTLA-4 [75]. The gene discussed is CD8A; the disease is colonic neoplasm.