PTEN and lung carcinoma: It has been demonstrated that MiR-214 gets transported into recipient CD4 + T cells by TEXs to downregulate the PTEN-mediated signaling, promoting Treg proliferation and tumor progression [135], and it is interesting to note that co-incubation of Treg with TEXs may increase Treg quantity as well as its suppressive activity in lung cancer [136].