Single cell cultures. Lin⁻/34⁺/DR^dim cells were sorted into 88 wells of 96-well plates with AFT024 stromal feeders using the FACS Star Plus ACDU system. Cells were cultured as indicated with weekly medium exchange. After 4 weeks, the content of each well was collected by trypsinization and divided equally over 8 secondary 96-well plates with pre-established AFT024 feeders in such a manner that one eighth of the content was deposited in the identical location in the 8 secondary plates, 4 for LTC-IC detection and 4 for NK-IC detection. To detect LTC-IC/NK-IC at day 0, single cells were cultured in 96-well plates containing AFT024 feeders for 5 weeks, and plates were overlaid with clonogenic methylcellulose. To detect NK-IC at day 0, single cells were cultured in separate 96-well plates containing AFT024 feeders as described in Materials and Methods. An ML-IC is defined as a single Lin⁻/34⁺/DR^dim cell with multilineage generative capacity, ie, this cell can generate at least one LTC-IC and one NK-IC.