The main goal of this work is to test whether it is possible to prove a theory about regulation of metastasis of cancer cells. The main idea of the theory is about stem cells which are wandering around in tissues and which are able to form new colonies of cancer cells (metastases). Some genes and pathways are said to be upregulated in those stem cells. With the gene expression data present for my work it could be possible to distinguish between cancer cells and healthy (normal) cells, and metastatic cancer cells and stationary cancer cells. The main difference of current work compared...