Similarly, using a zebrafish melanoma xenograft model, it has been demonstrated that in the presence of inherently invasive BRAF mutated (V600E) MITFlow WM266-4 cells, a poorly invasive sub-population of BRAF mutated (V600E) MITFhigh 501mel cells co-invades alongside invasive cells, suggesting cooperative interactions between phenotypically distinct sub-populations [227]. This evidence concerns the gene BRAF and melanoma.