p110β mRNA associates with and is translationally regulated by the fragile X mental retardation protein (FMRP), which is deficient in fragile X syndrome (FXS), the most common form of inherited intellectual disability and monogenic cause of autism (Gross et al., 2010; Sharma et al., 2010; Darnell et al., 2011). Here, FMR1 is linked to fragile X syndrome.