GPNMB and glioblastoma: Similar pathways were overrepresented in tumor vs. normal brain (SI Appendix, Fig. S3G) as found in 3D vs. 2D (Fig. 2E), and included additional tumoral processes, such as “PI3K-Akt signaling pathway” and “integrin cell surface interactions.” Interestingly, GPNMB, the most up-regulated SURFME protein in tumor vs. normal brain (SI Appendix, Fig. S3H) was previously identified as a tumor-associated surface antigen in human GBM (23), and a targeting ADC (glembatumumab vedotin) has entered clinical trials with several tumor types (24).