BMP2 and melanoma: While no difference could be found between proliferative and invasive melanoma cells for nodal expression (not shown), the four different datasets comprising a total of 101 proliferative, 90 invasive and 26 intermediate melanoma cell gene profiles yielded a significant up-regulation of BMP-2 in all four datasets in melanoma cells with the invasive phenotype compared to cells with the proliferative phenotype (Fig. 1A).