T cell mitogenicity in the presence of GFS whole extract in vitro. GFS extract assessed at 25, 125, 250 micrograms/ml (as1%, 5% and 10% of culture medium from a stock solution at 2.5 mg/ml). PHA and ConA were assessed at 1 mcg/ml. N = 3 in all cases. Blue bars indicate average readings, red bars indicate standard deviations.