PTEN and neoplasm: For instance, the mutation, loss or amplification of driver genes like PIK3CA, PTEN, or AKT (Kalbasi et al, 2020; Peng et al, 2016; Zhang et al, 2017) can aberrantly activate PI3K-AKT-mTOR signaling and promote the accumulation and immunosuppressive function of regulatory T (Treg) cells and tumor-associated macrophages (TAMs) within the local tumor microenvironment to augment immune suppression (Isoyama et al, 2021; Kaneda et al, 2016; Sun et al, 2021).