SALL4 and cancer: Having observed that SALL4 was enriched in HS/PCs that were identified by cell surface markers, we planned to evaluate the expression of this stem cell factor in SP and non-SP cells in various blood cancer cell lines (HL-60, NB4, KG1a and RPMI8226 cells), as well as investigate the role of SALL4 in drug resistance and cancer stem cells as identified by SP studies.