Fig. 1

Metastatic process of melanoma. 1. Melanoma cells may detach from the tumor in parallel to the growth of the primary tumor or in a linear process in which tumors first accumulate genetic and epigenetic alterations after which tumor cells disseminate. They undergo an epithelial-mesenchymal-like transition for higher invasive potential before entering the lymphatic or vascular system. 2. Melanoma cells circulate within the body and may adapt an endothelial phenotype within the vascular niche. 3. Melanoma cells occupy their niche and interact with the tumor microenvironment (TME) which includes extracellular matrix (ECM), cellular components and cytokines. They may undergo apoptosis, or either enter a proliferative or dormant state (created with BioRender.com)