SDC1 and glioblastoma: Co-IP assay disclosed that the SDC1 fragments containing the second constant range (SDC1-WT and SDC1-C1Vmut) but not the variable region nor the first constant range (SDC1-E307A, SDC1-E308A, SDC1-Y309 and SDC1-A310del) of cytoplasmic domain could bind to FLOT1 in GBM cells (Figure 7B).