CDKN2A and infection: As the strongest Arf interaction for EspG has been shown to be with Arf6 (Selyunin et al., 2011) and the specificity of EspG RabGAP activity is proposed to be determined by correct membrane targeting via ARF binding (Dong et al., 2012; Selyunin et al., 2014), we hypothesize that during infection EspG is sequestered by ARF6 at endosomal compartments, spatially restricting which Rabs EspG can inactivate.