CSPG4 IgE did not trigger RBL-SX38 cell degranulation in the presence of sera from human healthy participants, or from patients with melanoma, despite the absence of endogenous IgEs on FcεRI in this cellular model, meaning that CSPG4 IgE could fully occupy all available Fcε receptors and to thus trigger maximum degranulation. Here, CSPG4 is linked to melanoma.