A high degree of tumour infiltration by CD8+ T cells is strongly linked to a better prognosis in several types of cancer.91 It is known that immune-cell recruitment and activation relies on tissue-specific mechanisms, which vary across different tumour types92 and tissues, and might even present immune-cell contents that are distinct for different lesions from a single patient.93 Thus it is expected that PTEN deficiency in tumour cells could elicit effects on the TME that are tumour-type specific or even tissue specific. This evidence concerns the gene CD8A and neoplasm.