People who live past 110 have an unusual abundance of killer immune cellshttps://www.sciencedaily.com/releases/2026/08/260823014950.htm
People who reach 110 and beyond appear to have unusually large numbers of rare immune cells capable of killing abnormal cells. These CD4 cytotoxic T cells became more common with age and often expanded into large groups of nearly identical cells, suggesting the immune system was repeatedly responding to persistent threats.