PTEN and melanoma: Studies have shown that the murine model bearing PTEN-deleted melanoma tumors and PTEN loss leads to T-cell exclusion via two mechanisms: firstly, the inhibition of CD8+ T-cell killing and decreased effector T-cell infiltration through the expression of immunomodulatory cytokines, including CCL2 or vascular endothelial growth-factor (VEGF); secondly, reduced tumor immunogenicity by the inhibition of the autophagy pathway responsible for immunogenic cell death [43].