Evidence suggests that BAP1 inactivation in oral mucosal melanomas may play a role in tumor progression by promoting a more aggressive biological phenotype and reduced patient survival.45 Similarly, overexpression of heparanase, an enzyme released in the metabolism of tumor cells, also leads to poorer survival in oral melanomas, as they have a worse biological behavior.39 In oral mucosal melanomas, the transition from the radial growth phase to the invasive phase represents a critical step in tumor progression, as malignant cells migrate and infiltrate the underlying connective tissue. The gene discussed is HPSE; the disease is mucosal melanoma.