RAB39B and Cognitive impairment: To explore the mechanism underlying Rab39b-related cognitive deficits, there was evidence suggesting that Rab39b regulated the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) arrangement in the case of interaction with the PDZ domain of protein interacting with C-kinase 1 (PICK1), which was important for synaptic plasticity (Mignogna et al., 2015).