CXCL2 and glioblastoma: From the evaluation of the CXCL2 concentrations in our controls, we can conclude that the secretion only from the isolated OBSC rat brain cells or from the isolated GBM spheroid is not as high as the combination of the GBM spheroid and OBSC, i.e., interaction of the spheroid with the co-cultured cells from the OBSC leads to enhanced CXCL2-cytokine secretion.