Fig. 5.

The context‐dependent roles of SASP in tumour microenvironment. (A) Tumour‐suppressive SASP. In normal or precancerous tissue, senescent cells have a tumour‐suppressive role by re‐enforcing senescence through the SASP, which has both autocrine and paracrine effects. SASP factors can recruit immune cells to clear themselves (senescence surveillance). (B) Tumour progressive SASP. In advanced cancer tissue, SASP factors produced by senescent cells can promote cancer progression by enhancing angiogenesis, cancer cell proliferation, EMT and the metastasis of cancer cells. SASP factors also suppress anti‐tumour immunity. [Colour figure can be viewed at wileyonlinelibrary.com]