On December 9, in 2002, ISIS building was inaugurated, in the presence of some officials and state representatives, but also through a beautiful scientific symposium including François Diederich, Pierre-Gilles de Gennes and Harmut Michel. We are thus celebrating its 20th birthday today. The official celebration will take place later on in early 2023, but in the meantime, happy birthday ISIS, with a special thought for his founder Jean-Marie Lehn.