Table 1.

Effect of decreasing expression of superoxide dismutase genes on lifespan

Organism	No. of SOD genes	Effect of decreasing cytoplasmic SOD on lifespan, %	Effect of decreasing mitochondrial SOD on lifespan, %	Reference
Yeast	2	↓	↓	(9)
		↓63	↓63	(10)
		↓40	↓70	(11)
Worm	5		↓1 (NS)	(21)
		↓18	↓1 (NS)	(18)
		↓5 (NS)	↑15 (NS)	(19)
		↓3 (NS)	↑53	(22)
		↓20		(20)
Fly	2	↓80		(12)
			↓81*	(13)
			Lethality (<24 h)	(14)
Mouse	3	↓30		(15)
			Lethality (<10 d)	(16)
			Lethality (<18 d)	(17)

NS, Not significant.

*Sod2 levels were decreased by RNAi.