To fully characterize the extent of neurological deficits and establish an animal model to test future pharmacological interventions, we resorted to a heterozygous mouse model of APDS (E1020K knock-in mouse, further referred to as “p110δE1020K mice”) (Stark et al., 2018), to explore the effects of Pik3cd GOF on behaviour. The gene discussed is PIK3CD; the disease is activated PI3K-delta syndrome.