SH-SY5Y was cloned from a bone marrow biopsy derived line called SK-N-SH and first reported in 1973.[1] A neuroblast-like subclone of SK-N-SH, named SH-SY, was subcloned as SH-SY5, which was subcloned a third time to produce the SH-SY5Y line, first described in 1978.[2] The cloning process is essentially artificial selection, involving expansion of individual cells or a small group of cells that express a particular phenotype of interest, in this particular case neuron-like characteristic. The SH-SY5Y line is genetically female with two X and no Y chromosome, as expected given an origin from a four year-old female.