This family consists of A13L proteins from the Chordopoxviruses. A13L or p8 is one of the three most abundant membrane proteins of the intracellular mature Vaccinia virus [1].

1: Vaccinia virus membrane proteins p8 and p16 are cotranslationally inserted into the rough endoplasmic reticulum and retained in the intermediate compartment. Salmons T, Kuhn A, Wylie F, Schleich S, Rodriguez JR, Rodriguez D, Esteban M, Griffiths G, Locker JK; J Virol 1997;71:7404-7420. PMID:9311819