Abstract X-chromosome inactivation (XCI) in mammals is orchestrated by the noncoding RNA X-inactive-specific transcript (Xist) that, together with specific interacting proteins, functions in cis to silence an entire X chromosome. Defined sites on Xist RNA carry the N6-methyladenosine (m6A) modification and perturbation of the m6A writer complex has been found to abrogate Xist-mediated gene silencing. However, the relative contribution of m6A and its mechanism of action remain unclear.