Influences of FN fragments on hematopoiesis in vivo. BALB/C mice were intravenously injected with C274 or C-CS1 fragment of FN daily for 4 days at the indicated doses (n = 5 in each dose). The mice were killed at day 5, and subsequently the numbers of CFC in BM cells (1 × 10⁴) (A) and spleen cells (2 × 10⁵) (B) were assessed. The data are shown as mean ± SD. Control mice received an equal volume of PBS. Statistically significant differences from control values (shown at the left sides in each panel) are indicated by one (P < .05) or two (P < .01) asterisks. The figure shows one of two similar experiments. (▨), BFU-E; (▪), CFU-GM.