PITX2 and neoplasm: While αPD-1/αCTLA-4 therapy alone exhibited marginal growth inhibition of the YUMM3.3 tumors after 17 days of treatment, the addition of RGS to the αPD-1/αCTLA-4 regimen resulted in a significantly greater reduction in tumor volume (70%) (Fig. 4 g) as compared to RGS alone.