PLPPR4 and mental disorder: While PRG‐1+/− mice displayed no differences under normal conditions in tail suspension tests, following acute stress, PRG‐1+/− mice showed a significantly higher immobility (Fig 5B), indicative of alterations of resilient behaviors resembling aspects of stress‐related mental disorders (Cryan et al, 2005; Shen et al, 2008; Inta et al, 2010).