IGR-CaP1 tumors spontaneously disseminate to soft organs. Spontaneous metastases were observed in several organs, at week 31 after inoculation, as illustrated in the liver (A) and the lung (B). Metastases showed conserved expressions of invasive markers VIM and MMP-9. The prostate marker P504S was also conserved in the metastases. Magnifications: A, x100. B, HES, x50; insert, x200; Vim, x100; insert, x400.