In agreement, we expect that expression is related to escape genes rather than skewed inactivation, as shown for DDX3X and intellectual developmental disorders [7], BCOR and microphthalmia syndrome [8], KDM6A and Kabuki syndrome [9], OFD1 and orofacial digital syndrome [10], and USP9X and neurodevelopmental disorders [31]. The gene discussed is USP9X; the disease is neurodevelopmental disorder.