People also report ~2x differences in tumor death rates due to weird stuff like cage row though: "a strong correlation between cage row and RE (reticulo-endothe

People also report ~2x differences in tumor death rates due to weird stuff like cage row though: "a strong correlation between cage row and RE (reticulo-endothelial tumor) death rates, which varied from 17% (bottom row) to 32% (top row) (table 2)." http://www.ncbi.nlm.nih.gov/pubmed/6935460 http://www.ncbi.nlm.nih.gov/pubmed/6935460 Doesn't look like they controlled for that in the current paper. Who knows? In the extended figures they report a huge variation in median lifespan between different labs (like 33%, corresponding to what would be differences of 25-30 years for humans). It could have something to do with closeness to the door, air circulation, etc that people aren't thinking about. Maybe rodents gain some health benefit from being nearer the ground. Less stress when they look out the window?