NDFIP1 and memory impairment: Although we have shown that Beclin 1 and PTEN are both the endogenous ubiquitination targets of Nedd4 in the hippocampus, our results do not exclude the possibility that Beclin 1 and PTEN are also the ubiquitination targets of other Nedd family proteins involved in Ndfip1-mediated memory impairment.