GPT and melanoma: ALT-mediated TMM is commonly detected in tumors of mesenchymal and neuroepithelial origin [9,10,11], whereas it seems to be relatively rare in tumors of epithelial origin, although a consistent fraction of breast, gastric, and ovarian cancers, as well as malignant melanomas and neuroendocrine pancreatic tumors, have been reported to show ALT-associated features [10,11].