Despite other potential host physiological effects of dietary l-fuc (for example, microbiome, metabolome, etc.), these data confirm that l-fuc-induced itIC increases and melanoma suppression are critically mediated by melanoma-intrinsic expression and fucosylation of HLA-DRB1, which promotes its cell surface accumulation to trigger CD4+ T cell-mediated anti-tumor immune responses. Here, HLA-DRB1 is linked to melanoma.