Proposed model of PMT entry and trafficking. Tfn transferrin, TfnR transferrin receptor, CT cholera toxin, Rab5 GTPase marker of recycling endosomes, TGN trans-Golgi network, ER endoplasmic reticulum, SM/PC sphingomyelin/PC receptors of PMT, Arf6-CA constitutively active Arf6 GTPase, Arf6-DN dominantly negative Arf6, CcD cytochalasin D, LY294002 PI3 K inhibitor of early endosome-recycling endosome fusion, Noc nocodazole, BafA1 bafilomycin A1, Bfa brefeldin A. [Adapted from (Repella et al. 2011)]