Going critical

VERY slight changes in a cell’s nutrient supply can be crucial in cancer, say
Pier Delsanto and colleagues at the Polytechnic of Turin in Italy. They modelled
a grid of cells with cancerous ones at the centre. Near certain critical values,
tiny changes in levels of nutrients and how well cancerous cells can absorb them
determine whether tumours grow rapidly or regress, they found (Physical
Review E, vol 62, p 2547).