C9 and neuroblastoma: To decipher the protein interaction network of C9orf72, a SILAC (stable isotope labeling of amino acids in cell culture) based proteomic screen was performed in the neuroblastoma cells line neuro-2a (N2a) using GFP-C9orf72 (C9-L) as the bait and GFP as a control (Fig. 1a, Additional file 1: Figure S1).