Dear family, friends and colleagues, I'm deeply saddened by the sudden and premature departure of Arren. To me, he was one of the most inspirational researchers I've ever got to know. His work was outstanding, bringing elegant and fresh visions in the field of synthetic biology. We both shared this common goal, to create new microrganisms able to capture CO2 more efficiently, and one my biggest dreams as researcher was to work in his lab. Although we never met in person, we had a couple of videochats where he supported me to get on board and helped me in drafting my grant application. I'm very grateful for the time he took to help me. Despite the opportunity to collaborate didn't materialize at the end, my future research will be definitely inspired by his work. He's not completely gone, as he will continue to live in his visionary ideas and the beautiful pathways he created. Beyond the researcher, I'm sure there was a great and unique human too, as I could read from other people's thoughts. Sad I couldn't get to know him better. You'll be missed, Arren. Rest in peace. Alessandro