19 August 2015
Vol 7, Issue 301

About The Cover

Cover image expansion

ONLINE COVER Stiff Penalty for Obesity. Although known to be a major risk factor for breast cancer, how obesity drives disease is unclear. Seo et al. reveal that mechanical changes in the mammary environment—caused by obesity—may be the cancer culprit. The authors found that obese mice and humans had stiffer mammary extracellular matrices than their lean counterparts. In mice, myofibroblasts (spiky cell on cover) in fat tissue produced a stiffer matrix (in green) than usual, which stimulated premalignant cells to transform into cancerous ones. Caloric restriction in the mice decreased fibrosis, suggesting that a healthy diet could help reduce cancer risk. A related Focus is by Arendt and Kuperwasser. [CREDIT: H. MCDONALD/SCIENCE TRANSLATIONAL MEDICINE]