 GPC2 silencing inactivates Wnt/β-catenin signaling and reduces the expression of the target gene N-Myc, an oncogenic driver of neuroblastoma tumorigenesis.Immunotoxins and chimeric antigen receptor (CAR) T cells targeting GPC2 have been developed for treating neuroblastoma and other GPC2-positive cancers.Immunotoxin treatment inhibits neuroblastoma growth in mice.