To examine whether TRIM56 targeted K48-linked ubiquitination of cIAP1, IPs were performed to pull down cIAP1 in the GBM#P3-, LN229- and U118MG-sh-TRIM56-S1 and -S2 cells, and K48-linked ubiquitin was then detected with antibodies on western blot. Here, BIRC2 is linked to glioblastoma.