Oncogene-induced cellular senescence (OIS) is a complex program that is triggered in response to aberrant activation of oncogenic signaling.Initially,OIS was thought to be a barrier to malignant transformation because of its suppression on cell proliferation.Later studies showed that senescence induced by oncogenes can also promote the initiation and development of cancer.The opposing effects of OIS occur through different combinations of downstream effectors as well as the interplay of senescent cells and the microenvironment,such as senescence-associated inflammation.Here,we review the common features and molecular mechanisms underlying OIS and the interaction between senescent cells and the microenvironment.We propose that targeting senescent cells may have a beneficial therapeutic effect during the treatment of cancer.