highly significantP < 0.001
Inoculation with MDA-MB-231 (4175) LM2 cells increased the mean number of lung colonies in control animals by approximately 5-fold compared with MDA-MB-435 cells (67.6 ± 27.1 colonies vs 14.1 ± 1.6 colonies, respectively), a finding that was highly significant (Mann–Whitney rank sum test, P < 0.001).