FGF2 and neoplasm: In sham-injected control tumours, the hypoxic percentage increased from about 14% at day 15 postimplantation, (i.e. when sham- or FGF-2 injections were begun) to about 42% by day 22, and to about 75% at 29 days postimplantation (respective average volumes 220, 910, and 2810 mm3).