This family includes a group of uncharacterised proteins from bacteria. Recently, a member from Gemella sanguinis M325, Mbeg1 (for "microbiome bacteria effector gene") has been identified as the first example of this protein family being associated with a potential effector function in the human microbiome [1].

1: Functional Multigenomic Screening of Human-Associated Bacteria for NF-kappaB-Inducing Bioactive Effectors. Estrela AB, Nakashige TG, Lemetre C, Woodworth ID, Weisman JL, Cohen LJ, Brady SF; mBio. 2019; [Epub ahead of print] PMID:31744921