Comparison of the total number of human cells of the phenotypes shown found to be present in the tibias and femurs of mice transplanted with cells obtained from the marrow of primary mice transplanted with human cord blood cells and administered either no further treatment (open symbols) or FL, SF, and IL-6 (solid symbols) at a low dose, daily (A), or at a high dose three times per week for 2 weeks (B). Data pooled from the two experiments described in Table 2. Each symbol denotes an individual secondary mouse. The corresponding % human (CD45/71⁺) cell repopulation values for the marrows of these secondary mice that contained greater than 0.1% human cells ranged from 0.1% to 12%.