Mixed hematopoietic chimerism is proven to lead to immune tolerance after bone marrow transplant (BMT) and can reduce graft-vs-host disease (GVHD)-related mortality. It can be achieved with chemotherapeutic agents or strategies that block activation of donor or depletion of host T cells. Immune conditioning with helminthic commensals regulate the host immune system and promotes a transient mixed chimerism. Conditioning with helminths induces IL4 production via host Th2 pathway and regulates GVHD while preserving graft-versus-tumor effect. IL4 signals through IL4 receptor (IL4R) and STAT6. We hypothesize that induction of host Th2 pathway is critical for achieving mixed chimerism by intestinal immune conditioning