A special issue of dedicated to the 20th IUPAB (virtual) Congress "in" Foz do Iguaçu.

The 20th IUPAB Congress took place online, together with the annual meetings of the Brazilian Biophysical Society and the Brazilian Society for Biochemistry and Molecular Biology, from the 4th to the 8th of October, 2021. The ten keynote lectures, 24 symposia, two poster sessions, and a series of technical seminars covered the full diversity of current biophysical research and its interfaces with other fields. The event had over 1000 attendees, with an excellent gender balance. Although the Americas dominated, there were also significant numbers of participants from Europe, Asia, and Africa.