ARL6IP1 and neuroblastoma: We observed overexpression of ARL6IP1, the substrate of HuD, significantly protects cells against HuD silencing (Fig. 7B and S6B) in NB cell lines (IMR-32, SK-N-SH and SK-N-DZ); moreover, silencing of ARL6IP1, by itself, reduces cell viability (Fig. 7C and S6C) and its forced overexpression partially compensates for HuD knockdown (Fig. S6D).