Sorafenib activity in OS xenograft models. In three different experiments, one group of mice was injected s.c. into the right flank with U20S and one group of mice was injected e.v. with SJSA-1 cells. Five mice per group were orally treated daily with sorafenib (0-10-30-100 mg/kg/die) for 16 days as described in the Materials and Methods section. (A) Sorafenib reduces tumour volume OS xenografts in SCID mice. The graph indicates the mean tumour volume (mm3) measured using calipers at 0, 7 and 16 days of sorafenib treatment (Error bars: standard deviation). (B) Sorafenib reduces blood vessel number. The graph shows the mean number of patented blood vessel +/- standard deviation calculated in 10 fields at 40× magnification on Masson's trichromic staining.