ARL6IP1 and cancer: In our experiments, regulation of the RNA levels for HuD substrates GRB-10 and ARL6IP1 also occurred in mouse xenografts where silencing of HuD led to drops in the mRNA levels of GRB-10 and ARL6IP1, shown to bind and be stabilized by three versions of HuD (native and FLAG-tagged in cancer cells and purified GST-HuD protein from E. coli).