Similarfindings have been reported by Weng et al. in hepatocellular carcinomain mouse models.45 These findings are mostlylikely due to increased MHC class I expression, as a strong correlationwith T cell infiltration has been found in melanoma.46 While the cause for the unchanged CD4+ T cell numbers remainsunknown, the decreased CD4+/CD8+ T cell ratio holds immense significance.CD8+ T cells are also known as cytotoxic T cells, given their functionof eradicating malignant or infected cells. Here, CD4 is linked to melanoma.