Impaired tumor angiogenesis in Cd151-null mice. (A) LLC tumor growth was assessed in 10 age- and sex-matched WT and knockout (KO) mice. Data are representative of 5 independent experiments. From tumors such as shown in the photo, tumor volume and tumor weight were calculated (n = 10; *P < .05). (B) Cryosections of LLC tumors were stained for endothelial marker CD31 and the number of CD31⁺ blood vessels was counted (*P < .01). Scale bars represent 1 cm (A) and 100 μm (B).