Similar to our findings in patients with anti–PD-1–treated NSCLC and melanoma, mice consuming sucralose were resistant to PD-1 blockade in both MC38 (circles) and B16 (squares) and had significantly increased tumor growth, less CD8+ T-cell infiltration, and reduced survival across multiple tumor models (Fig. 2B–D; Supplementary Fig. S4A–S4E). Here, PDCD1 is linked to melanoma.