MKI67 and glioblastoma: Consistent with prior findings of SOX2 being a key determinant of ZIKV infection (Zhu et al., 2020), the proportion of cells positive for SOX2 was higher in MR than HR GBM samples (Figure 2C; Figure S2E), whereas there was no significant difference in the fraction of cells labelled by the proliferation marker MKI67 (Figure S2F).