Once upon a time (in 2011 to be a bit more precise), Gliese 581 d was touted as the first life-friendly exoplanet.
Now, it seems that some folks were a bit too hasty. According to an article in New Scientist:
“New analysis of the Gliese 581 star system suggests that signals previously attributed to two of its six suspected planets actually come from sunspot-like regions on the star itself. The same analysis builds support that three of the other four planets are real, but none of these worlds would be able to support life as we know it.”