RSU1 is a protein that is involved in the ras signal transduction pathway, growth inhibition, and nerve-growth factor induced differentiation processes, as determined in mouse and human cell line studies. In mouse, RSU1 was initially isolated based on its ability to inhibit v-Ras transformation. Multiple alternatively spliced transcript variants for this gene have been reported; one of these variants was found only in glioma tumors. Recombinant human RSU1 protein, fused to His-tag at N-terminus, was expressed in E.coli.