The synergistic effect with programmed cell death protein 1 (PD-1) antibody therapy was also evaluated.<h4>Results</h4>Thimerosal potently inhibited tumor growth (with IC<sub>50</sub> values ranging from 0.1 to 1 μM <i>in vitro</i>) and significantly prolonged survival without overt toxicity <i>in vivo</i>. This evidence concerns the gene PDCD1 and neoplasm.