Makoto Kinoshita (Nagoya University, Japan) was the first to hypothesize the possibility of paralog human septins (i.e., septins from the same group) occupying always the same position within the filament. This is now known as the Kinoshita’s rule.

Possibilities of different septin octamers according to the Kinoshita’s rule. Considering that only one septin from each group can participate in the oligomer, there are 60 different variations (without considering the different isoforms). For hexamers, this number is 20.