Figure 3. Circuits that mediate paracrine interactions between senescent cells and surrounding environment. According to experimental results and literature data we propose: MMP2 and TIMP2 may play a key role in pathways regulating the effect of senescent secretomes on cancer cells; IGFBP3 and PAI-1 are part of the paracrine circuit that induces senescence in neighboring cells; and PRDX6, ERP46, PARK7, Cathepsin D, and MVP could be part of the common circuit that allows senescent cell survival following stress.