The scale of the Class C β-lactamases phylogeny makes it impossible
to visualize the detail of the β-lactamases from Citrobacer freundii (CFRE).
Those gene recently moved onto plasmids and have diversified, albeit only slightly,
from each other. This page therefore includes both the phylogeny of the Class C
β-lactamases, and a separate, detailed phylogeny of the CFRE clade within the
Class C β-lactamases.