TACR1 and glioblastoma: Furthermore, in glioma samples, also called glioblastoma (grade 4 astrocytoma), all samples studied (10 of 10 [5] and 17 of 17 [6]) express NK-1Rs and, in the case of astrocytoma samples, 9 of 12; also, NK-1R density was more marked and more extensive in gliomas than in astrocytomas [5,7].