Dear family, friends and colleagues, I am very sorry for such a big loss! We will all miss Arren. I had the great opportunity to work in Arren’s group. From the first day I realize he was special. Very direct, incredibly intelligent, funny, transparent, but under that strong personality, there was a big heart. I admired your wisdom, you taught us a lot and I will always appreciate you believed in my work and gave me the opportunity to work with you. Your work was an inspiration to many of us and a breakthrough for the scientific community. Thanks for letting me be part of your group, or properly said, your family. Sincerely, Sara Benito