FMR1 and fragile X syndrome: Even though most Fmr1-KO mice displayed similar learning curves than control, during the shaping learning curves (where the animal learns the behavioral task itself) Fmr1-KO made more errors during the learning process with some Fmr1-KO not being able to reach criteria at all (Larson et al., 2008), emulating the intellectual deficits found in the majority of individuals with FXS (Hall et al., 2008).