Changing of the weather...an extensive study on how your DNA changes with the seasons.
"The question is slap-your-forehead simple: How do genes respond to seasonal changes? Surprisingly, nobody had yet looked. “We knew that there are some genes that change their expression throughout the day, and then it hit us—like BLAM!—what is the effect on genes of the length of day throughout the year?” says Chris Wallace, an immunogeneticist at Cambridge University."
http://www.wired.com/2015/05/dna-changes-seasons-just-like-weather/
Detailed and scientific report
http://www.nature.com/ncomms/2015/150512/ncomms8000/full/ncomms8000.html


Your DNA Changes With the Seasons, Just Like the Weather | WIRED
www.wired.com
In the winter, your blood contains a denser blend of immune responders, while summer veins swim with fat-burning, water-retaining hormones.