Interestingly, HLA-class I APM component levels (Delta, LMP-7/10, TAP-1, Calnexin, Tapasin, β2-microglobulin, and HLA-A,B,C) were lower in immature epidermal LCs compared to melanoma-positive SLN LCs, and significantly increased after LCs maturation. Here, TAP1 is linked to melanoma.