Tateishi and Iwaki’s group were investigating αB-crystallin (CRYAB), a well-known small HSP, for a long time, and found that the CRYAB protein is mainly expressed by astrocytic tumors among neuroectodermal neoplasms, frequently observed among astrocytic tumors, schwannomas, hemangioblastomas, and chordomas, and discovered that these pathological brain lesions cause an abnormal elevation in the potassium (K+) concentration of the extracellular space [48,49,50]. This evidence concerns the gene CRYAB and primitive neuroectodermal tumor.