NANOG and Huntington disease: Neuroinflammation signaling pathway, axonal guidance signaling, role of NANOG in mammalian embryonic stem cell pluripotency, glioblastoma multiforme signaling, amyotrophic lateral sclerosis signaling, TGF-β signaling, synaptic long-term potentiation, Huntington’s disease signaling, neuropathic pain signaling in dorsal horn neurons, glioma invasiveness signaling, synaptogenesis signaling pathway, and glioma signaling