By inhibiting hIDO1 and hTDO2 enzymes, Pitavastatin prevents the formation of immunosuppressive metabolites, thereby weakening the immunosuppressive tumor microenvironment. This enhances T-cell-mediated cancer cell elimination via caspase-3 activation, making it a promising candidate for oral squamous cell carcinoma treatment. Here, CASP3 is linked to oral cavity squamous cell carcinoma.