In summary, the author of the article linked below writes:
TRAPPIST-1 is one of the most intriguing exoplanetary systems known.
Scientists are getting closer to finding out what conditions are like on the TRAPPIST-1 exoplanets.
A new study suggests that at least some of the TRAPPIST-1 exoplanets likely have hazy or cloudy atmospheres, and at least one may have a clear hydrogen atmosphere.
Finding out what kind of atmospheres these worlds have, can help scientists understand whether any of them could possibly support life [as we know it].