What do you think is this reasonable or just theory for the sake of headlines?  Here is more on the specific areas they think may differ:

In the research, they discussed how, while life on Earth has a unique biochemical toolset, life on Mars or even Titan could survive with a few adaptations. On Earth, for the most part it requires oxygen, nitrogen and other key ingredients to survive, in addition to storing information via DNA and RNA, which is why we look for these things on other worlds.

But that might not be the case everywhere. One example is that a water-hydrogen peroxide mixture, rather than water, could be used in the cells of small microorganisms on Mars, whereas those on Titan could use liquid methane or ethane. Some other chemical process aside from DNA could store information as well.

Note the pic above is from the 1970s and they weren’t looking for other types of evidence as suggested in this research.

I would definitely like to hear more on how they would search for these other types of biological processes in the future.

And here is a video of some cool pics from the Mars Curiosity Rover in 2015.

thanks to iflscience.com for the great info