Final act of senescence

摘要

Cellular damage is unavoidable and intrinsic to life, and it is often aggravated by pathogens or exposure to toxic agents. In long-lived multicellular organisms, however, damaged cells pose a problem not because of their loss of function, but mainly because their proliferation can escalate a minor local problem into a deadly cancer. Fortunately, cells can detect their own level of damage and eventually dismiss themselves in a final act of altruism for the benefit of the organism. Self-dismissal comes in two forms, apoptosis (self-destruction) and senescence (self-disabling), with the latter being at least as prominent as the former in providing protection against cancer1'2. On page 547 of this issue, Kang et al.3 explore how the immune system targets senescent cells to limit the development of liver cancer.