Based on limited published evidence, PEX39 is a cytosolic peroxin that facilitates peroxisomal protein import through the PTS2 (peroxisomal targeting signal-2) pathway. PEX39 binds PEX7 and stabilizes its interaction with PTS2-containing cargo proteins via an (R/K)PWE motif 1. After PTS2 cargo is imported, PEX39 extracts PEX7 from the peroxisomal membrane's YG phase on the cytosolic side and reloads it with new cargo to initiate subsequent import cycles 2. This handover mechanism between PEX39 and the membrane translocon PEX13 represents a novel paradigm for peroxisomal protein biogenesis.