Dual checkpoint blockade, such as the combination of ipilimumab (CTLA-4 inhibitor) and nivolumab (PD-1 inhibitor), has demonstrated superior efficacy and received FDA approval for multiple cancers, including melanoma, NSCLC, RCC, HCC, and microsatellite instability-high (MSI-high) colorectal cancer (Livingstone et al., 2022; Olson et al., 2021; Wolchok et al., 2022; Butterfield and Najjar, 2024). The gene discussed is CTLA4; the disease is melanoma.