ZKS cells support hematopoiesis. (A) All hematopoietic cell populations are represented in CFSE⁺ cultures. Representative flow cytometric light scatter profile showing the different populations of cells present in CFSE-labeled WKM at day 0, before plating on ZKS. (B) ZKS support cell survival. Total cell numbers of WKM cultured with ZKS cells (—▲—) and without (---●---) over time (n = 4). (C) Lymphoid, precursor, and myeloid cells all survive over time. Total number of lymphoid (left), precursor (center), and myeloid (right) cells present in WKM cultures with ZKS cells (—▲—) and without (---●---; n = 4). In all cases, total cell numbers are given at left, and days in culture are given at bottom. In all cases, the graph depicts the mean and SD for 4 independent replicates.