Figure 1.

A just-so story about mitochondria and cell death. According to this tale, an early archaeal cell defends itself by committing suicide when infected (upper pathway), but, when faced by a variant bacterium possessing by chance the wherewithal to interfere with the archaeal cell's defenses (lower pathway), the archaeal cell is subjugated by the invader. Over time, the invader repays the cell by developing into the cell's mitochondrial powerhouses that still retain the ability to act as lynchpins of cell death regulation.