If you’ve been feeling more than usually guilty about the environment since Tuesday, September 23, there may be a reason: that was the day humans used up all the resources—on cropland, pasture, forests and in fisheries—that nature will provide this year, according to data from the Global Footprint Network, a research group. By the end of the year, we will have used the biological capacity of 1.4 planets, which is only possible, of course, by drawing on the store of resources from previous years.

There’s a lot of research these days aimed at identifying characteristics of cancer cells that make them susceptible to particular treatments, as breast-cancer cells with extra expression of the her2 protein are treatable with Herceptin. Equally important, it seems to me, is identifying cancers that will not respond to standard chemo, which can be hugely debilitating. It would be a great help to patients if doctors could tell before administering a single dose whether the chemo will help.

Now scientists at MIT have shown, in a paper in the online edition of the journal Genes and Development, that 48 specific genes explain a good deal of the variation in whether malignant cells will be killed by chemo.

The old-line chemo drugs, such as those based on platinum compounds such as oxaliplatin, work by damaging DNA. That prevents malignant cells from multiplying. But the MIT scientists find that a group of 48 genes can predict how susceptible a patient is to a toxic compound called MNNG that, like common chemo agents, kills cells by inducing irreparable DNA damage. Which of the 48 genes someone has produces huge variability in response to DNA-damaging compounds. “A cell line from one person would be killed dramatically, while that from another person was resistant to exposure,” said Rebecca Fry, former MIT research scientist and lead author of the paper who is now at the University of North Carolina School of Public Health. “It wasn’t known that cell lines from different people could have such dramatic differences in responses.”