PTEN and melanoma: PTEN, another essential tumour suppressor, regulates the production of immunosuppressive cytokines by melanoma cells.42 In human melanoma, PTEN deletion was correlated with a decrease in infiltrating CD8+ T cells.18 In HGSOC, however, we observed no correlation between the expression level of PTEN and the number and/or localisation of CD8+, CD45RO+and CD68+ leucocytes in the tumour microenvironment or the PCs we derived.