SP^KLS cells and SLAM cells are functionally overlapping populations. Non-SP cells can be found in significant numbers within the SLAM isolation scheme (particularly when using isotype controls to define the population), and these non-SP cells are not functional HSCs. Further, CD150⁻ cells can be found within the SP^KLS sort scheme. The gray area represents populations containing LT-HSC activity, with the darker gray central area representing the less proliferative myeloid-biased LT-HSCs. The area within the Venn diagram is roughly representative of the degree of overlap, but not precisely to scale.