PRMT5 and neuroblastoma: While testing the potential of AKT1-R391 being a substrate of PRMT5 in neuroblastoma, we found that the ectopic expression of AKT1-R391K mutant is significantly lower compared to AKT1 wild type and R15K mutant even in the presence of proteasome inhibitor MG132 (Supplementary Fig. 5e).