PTEN and neoplasm: Multiple pathways and aberrations in tumor cell signaling such as the Ras/MAPK pathway85, WNT/β-catenin86,87, PTEN/PI3K pathways88 and a novel transcriptional program termed IPRES (innate PD-1 resistance)89 have been analyzed in terms of their associations with absence of a T cell infiltrate and anti-tumor immune responses.