CD4 and neoplasm: This approach is particularly promising as UM is not only characterized by a low mutational burden, but also potential immune escape mechanisms: the eye is an immune-privileged site that could help tumour cells to escape immune elimination [42]; the tumour-infiltrating lymphocytes (TILs) cultures expanded from UM show predominant CD4+ T cells, whereas TILs from CM are CD8+ and more reactive against autologous tumours [43].