Table 2. Melanoma cells undergo reversible changes in tropism during metastasis.

a) Schematic and limiting dilution analysis of the frequency of melanoma cells from subcutaneous tumours, the blood (circulating cells), or metastatic nodules that formed tumours after subcutaneous, intravenous, or intrasplenic transplantation. These data reflect three independent experiments performed with efficiently metastasizing melanomas (M405, M481 and UT10; n=10 mice/melanoma/melanoma cell source/transplantation site for a total of 270 mice). b) Schematic and limiting dilution analysis of the frequency of melanoma cells from subcutaneous tumours, the blood (circulating cells), or metastatic nodules that formed tumours after being passaged subcutaneously in primary recipient mice and then transplanted subcutaneously, intravenously, or intrasplenically into secondary recipient mice. These data reflect one experiment performed with efficiently metastasizing melanoma cells (M481; n=8–10 mice/melanoma cell source/transplantation site for a total of 85 mice). Statistical significance was assessed by a chi-square test using ELDA software⁴⁶

^*p<0.05;

^**p<0.005;

^***p<0.0005.