HLA-DRB1 and melanoma: To assess correlations of (1) tumor-specific fucosylation and total/fucosylated HLA-DRB1 of individual tumor cells and (2) intratumoral numbers CD4+ T cells with responder status to single-agent anti-PD1 therapy, we implemented L-PLA on primary melanoma biopsies from two distinct responder and two non-responder patients followed by single-cell segmented signal quantitation (Fig. 7a,b).