CLDN6 and Nephroblastoma: Indeed, expression of CLDN6 has previously been shown in malignant rhabdoid tumors (MRTs), Wilms tumors (WTs), hepatoblastoma, germinoma and extracranial GCT [15,16,17,18], Thus, CLDN6 could represent an important target for CAR-T cells and monoclonal antibody-based therapies in the pediatric population.