The transport of H2O2 across membranes by specific aquaporins (AQPs) has been considered
the last milestone in the timeline of hydrogen peroxide discoveries in biochemistry.
According to its concentration and localization, H2O2 can be dangerous or acts as
a signaling molecule in various cellular processes as either a paracrine (intercellular)
and/or an autocrine (intracellular) signal. In this review, we investigate and critically
examine the available information on AQP isoforms able to facilitate H2O2 across biological
membranes ("peroxiporins"), focusing in particular on their role in cancer. Moreover,
the ability of natural compounds to modulate expression and/or activity of peroxiporins
is schematically reported and discussed.