Next, we performed a PLA assay to detect the colocalization of Sortilin and Presenilin1 and found significant Presenilin1-Sortilin PLA signaling in U87 and U251 cells, suggesting that Presenilin1 was located in close proximity to Sortilin in GBM cells (Fig. 3J–K). The gene discussed is SORT1; the disease is glioblastoma.