When comparing the proteins expressed by MCF-7 o/e Snail cells with those expressed by the tumor tissue created by intra-tibia injection of MCF-7 o/e cells, which is denoted as MCF-7 o/e Snail tissue from hereon, it was found that the former showed an EMT expression pattern, namely, increased N-cadherin, Vimentin and Snail and decreased E-cadherin expression, while the latter showed opposite reciprocal changes in these proteins, namely a MET pattern, either at protein level (Fig. 3a, b) or at transcriptional level (Fig. 3c–e). This evidence concerns the gene SNAI1 and neoplasm.