FMR1 and neuroblastoma: In agreement with the observation that FMRP co-localizes with PABPC1 and granule constituents in polarized, i.e., differentiated, human SH-SY5Y neuroblastoma cells [4], we propose the existence of a translationally repressed granule — an NMD-silenced complex — that contains FMRP-bound NMD targets, protected from mRNA decay and transported to neuronal projections (Fig. 1b).