Subsequently, we observed that another acyclic retinoid, GGA [XI], like ATRA [X], also inhibited the proliferation of the neuroblastoma-derived cell line SH-SY5Y cells, induced neuron-like morphological changes, and significantly induced the expression of the neurotrophic receptor tyrosine kinase-2 (NTRK2 or TrkB) gene, a putative BDNF receptor (35). Here, NTRK2 is linked to neuroblastoma.