PMEL is a 100 kDa, 661 amino acids long type I transmembrane glycoprotein that is expressed primarily in melanosomes, which are the melanin-producing organelles in melanocytes of pigment cells of the skin and eye, and in most malignant melanomas.

After the amyloidogenic region is cleaved, the small remaining integral membrane fragment is digested by γ-secretase.

[9] Hydrophilic recombinant gp100 protein (HR-gp100) has been topically applied on human intact skin in vitro, and used as a vaccine in a mouse model.

In the mouse model, an HR-gp100-based vaccine triggered antigen-specific T cell responses, as shown by proliferation assays, ELISA and intracellular staining for IFN-γ.

According to a case study, modifications of GP100, such as GP100-209 and GP100-208, have shown a greater number of antigen-specific CTL's (cytotoxic T lymphocytes), which can target and kill cancer cells (Eisenberg).