<qa>  What is a multi-institutional Pilot clinical trial of hematopoieticThis is a multi-institutional Pilot clinical trial of hematopoietic stem cell transplantation HSCT for i patients with recurrent chemo-responsive malignant high-grade neuro-epithelial and other solid tumors which are recurrent following HSCT or ii for said patients without autologous hematopoietic progenitor cell availability. The stem cells will be derived from a 1 matched related donor or 2 matched unrelated donor MUD. 