Of special interest, by replicating the BM microenvironment in leukemia patient-derived organoids (PDO), our recent findings have revealed a CXCL11+ hematopoietic niche in childhood leukemia that display a unique signature and support leukemia initiating cells (Balandrán, 2019-2020, unpublished data). The gene discussed is CXCL11; the disease is leukemia.