SLC2A1 and glioblastoma: However, tissue hypoxia, as quantified using Hypoxyprobe‐1 and GLUT1 expression (an alternative hypoxia marker), was not meaningfully observed within the thyroid gland of control, T4‐treated, or PTU‐treated mice, while they were highly detected in the hypoxic regions of implanted glioblastoma (positive control; Appendix Fig S4).