Fig. 2. K1735 melanoma metastasis requires expression of ß3 integrin. 2x10⁵ M2 (A), M2-Tß3 (B), C23 (C), or C23-mß3 (D) cells were injected subcutaneously into the hind flank of C3H/HeN mice. After 12 weeks the mice were sacrificed and analyzed for metastases. On average 100 colonies (±20) were formed by M2 (A, arrows) and 40 lesions (±10) by the C23-mß3 cells (D, arrows). By contrast, M2-Tß3 (B) and C23 cells (C) did not form pulmonary metastases. Quantitation of the experiment is shown in E.