FOXO1 and mantle cell lymphoma: But despite its ability to reprogram AML cells, it is worthwhile to note that forced FOXO1 expression in HeLa or HEK295T cells of non-hematopoietic origin could not reprogram the cells nor promote other MCL lineage-survival TF expression (Supplemental Figure 4, H and I), implying that an appropriate cellular context is required for FOXO1 to carry out its lineage-priming function.